Methods and Compositions for Preparing Consumables with Optical Shifting Properties

ABSTRACT

Ingestible compositions comprising a chromic change agent together with methods of making and using them are provided. The chromic change agent alternatively may be associated with the ingestible, such as a packaging material for the ingestible. In response to a triggering event, physical or chemical, the chromic change agent changes color to provide information as to the history of the ingestible, either prior or contemporaneous with use. Depending on the use, the color change agent may be reversible or irreversible. Various solid or liquid ingestible compositions are provided for determining ingestible temperature, storage temperature, user temperature, light exposure, pH change, hydration or solvation change, mechanical stress, and the like, particularly in comestibles. Of particular interest are polydiacetylene polymers that may be formulated to provide compositions having numerous different color transition triggering mechanisms. The invention is also related to other chromic change agents that may be incorporated into ingestibles.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. Ser. No. 09/892,018filed Jun. 25, 2001 which is a continuation in part of U.S. Ser. No.09/602,001 filed Jun. 23, 2000, which disclosures are herebyincorporated by reference.

INTRODUCTION

1. Technical Field

The field of this invention is methods and compositions for preparing anedible consumable or ingestible comprising one or more chromic changeagent that is safe for human or animal consumption that interactivelymodulates a color transition in the edible consumable or ingestible.

2. Background

Foods, beverages, medications and a variety of edible products withintrinsic color change properties can find a multitude of uses formanufacturers and consumers alike. They can be developed and marketedfor entertainment purposes, such as graphics on the surface of food thatchange color, giving rise to a visual effect that is both pleasing andinteresting for children. A variety of new food categories can beproduced to contain the chromic material. Food producers are in need ofnew means to differentiate brands, extend product lines, advertise andpromote, and create new product lines. Generally, food developers arelimited to new flavors, colors, presentations, packaging, andcombinations for product differentiation. Entirely new categories offoods, beverages, and medications can be created by introducing a newintrinsic property during processing.

Color changes may release or expose hidden messages which can be usedfor promotional or marketing purposes. Color changes can visually signalthe consumer when the food is “done” to a satisfactory extent and safeto eat, or that the food is still in the process of being cooked. Colorchanges can be used to communicate optically with a cooking instrumenttelling the cooking instrument the level of doneness through a bar codechange.

Color change foods can indicate to consumers or institutions that thefood offered is sterile due to its color at purchase. Subsequent changesin color could indicate that the food has become stale or spoiled. Safefood storage temperatures can be indicated by the food or beveragedirectly where a color change indicates that the food was held at aninappropriate temperature for a period of time. The color change can beused to signal the timely release of a certain nutrient or flavor intothe food. The chromic change can also be used to communicate the natureof food to be consumed. For example, chromic change agents can tell theconsumer how “hot” a hot sauce really is, the fat content of certainfoods, the level of carbonation in soft drinks, or the level of abiological or chemical in a food, such as caffeine or allergens.

Certain spices and other foods should be irradiated with high-energysources to ensure that potential microbial contamination has beeneliminated, thereby protecting the consumer. Foods containing a chromicagent that changes color upon irradiation can communicate to theconsumer or the food processor that proper irradiation has taken place.

RELEVANT REFERENCES

Colored food products on the market today involve the use ofcommercialized dyes combined with a capsule of waxes or other opaquematrices that mask the underlying dye. The dye molecules become visuallyexposed upon dissolving or melting of the encapsulating material. Anexample of releasing a dye into hot water involves Quaker Oat's DeepBlue Hot Oatmeal. An example of dissolving a coated dye into cold milkinvolves a version Nabisco's Oreo Cookie that releases a blue dye intomilk when the cookie is dipped into the milk. An example using meltingwaxes to reveal an underlying color involves Kellogg's PopTarts where awhite wax is coated over a colored sprinkle. When the pastry is heatedthe wax melts to reveal the color. An example of beverage additive isKraft Food's Kool-Aid Magic Twists incorporating an entrapped dye thatbecomes revealed as the coating on the food color is dissolved. Anexample of a color change when a food product is eaten is FritoLay'sCheeto's Cheese Puffs, which release a dye into one's mouth when theproduct is wetted and chewed. An example of a chewing gum which turnsone's mouth blue is Blue Mouth Chewing Gum from Creative ProductsManufacturing. In each case a color is revealed by releasing or exposinga hidden dye and not an intrinsic chromic change that results from amolecular change in the chromic change agent itself.

References of interest include U.S. Pat. Nos. 4,859,538; 5,144,112;5,156,810; 5,189,281; 5,273,360; 5,415,999; 5,685,641; 5,788,375;5,918,981; and 6,046,455.

SUMMARY OF THE INVENTION

Environmentally responsive components are intrinsically associated withingestibles, such as foods, beverages and medicaments, to be consumed aspart of the ingestible, while providing knowledge of an informative orentertaining character. Specifically, physiologically acceptable chromicmaterials, e.g. polymerized polyacetylenes, are associated with theingestible so as to be consumed by the user. The chromic materialchanges color in response to various environmental clues, such astemperature, pH, radiation, and physical stress, among others.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

Ingestibles are provided comprising a chromic material that changescolor in response to environmental cues.

A variety of color change triggering processes can be used to cause thecolor change of chromic change agents depending on the type of chemistryinvolved, such as temperature, pH changes, changes in ionic strength,mechanical changes such as stress or pressure during mixing orcontortion, chemical changes such as the addition of a second component,exposure to light for a photochromic effect, biochemical reactions suchas binding pair interaction (e.g., an antibody-antigen interaction, areceptor-ligand interaction), solvent environment changes, hydration ordehydration, solvent changes, and enzymatic changes where enzymes in thefood can induce a change. The color-indicating material can be processeddirectly into the ingestible, coated on the surface, released in atimely manner, or be made to be exposed through a discrete color changetriggering process.

By ingestibles is intended compositions that are taken orally, eventhough they may not be digested. Therefore, ingestibles include foods,medicaments, toothpaste, mouth washes, gargles, swabs, and the like,where the food is introduced into the mouth and may then be rejected ormay reside in the mouth for a limited period of time. Since foods arethe primary application of the subject invention, foods are discussed asillustrative of ingestibles generally. The chromic materials arephysiologically acceptable, particularly polymerized polyacetylenes,which can be incorporated with the ingestible during or afterprocessing. Only a small amount of the chromic material need beincorporated, where the chromic material may be suffused through theingestible, partially penetrate the ingestible or primarily be anadherent coating on the ingestible. The ingestible is porous or liquid,so that the chromic composition, by itself or in conjunction with anedible carrier, interpenetrates the ingestible, where the penetrationmay be throughout the ingestible, a limited depth into the ingestible,or into the surface to provide an adherent surface.

Polydiacetylenes as a class of ingestible chromic agents offer severaladvantages since they exhibit a broad range of beneficialcharacteristics. They have a large extinction coefficient showing a highcolor contrast, so that proportionally less chromic change material maybe required to achieve an optical effect than materials such asentrapped dyes. Polydiacetylenes are organic and can be modified tocreate a wide range of permutations applicable to different chromictriggering mechanisms, ingestible applications, and processing methods.They can be structurally modified to have more than one intrinsic colorchange (e.g. blue-magenta-red or blue red-yellow). They can be modifiedto be compatible with the different food matrices (e.g., fats, aqueous,starch, protein, inorganic salts, sugars or the like). They can be madestructurally inert such that they are odorless and tasteless, thus notaffecting the foods to which they are added. The polymer form is a highmolecular weight structure thereby, reducing its potential foradsorption during the digestion process. Polydiacetylenes are compatiblewith a variety of compositions used in the food industry for coatingsand processing, making them amenable to existing processing methodswithout complete processing line redesign (e.g., solid food forms orliquid food forms). They can be made into stable forms making them goodcandidates for tolerating the stresses of production, shipping andstorage.

Polydiacetylenic and other chromic change materials that undergo anintrinsic color change respond directly to a triggering event ratherthan simply releasing a color. A direct response chromic change has thesignificant advantage that the chromic agent itself can be engineeredand designed to meet a broad and varied interest in the food,pharmaceutical and other relevant industries. In the case ofpolydiacetylenic materials, the chromic agent can be chemically enhancedwith different substituents and functional groups for variousapplications while maintaining the intrinsic color changecharacteristics. The unique conformational change mechanism thatpolydiacetylenes undergo during a color-changing triggering eventprovides a unique means to match the material with food-basedchemistries, food processing methods, and printing and applicationprocesses.

Since polydiacetylenic materials can be modified to change color to avariety of different optical triggering mechanisms, they have theadditional advantage that they may serve as indicators or reporters fora variety of different monitoring processes of interest to the food andpharmaceutical industries and consumers. Examples of such monitoringprocesses include cooking temperatures, presence of toxic chemical ormicrobial contaminants, heavy metal, the presence of carcinogens,allergens that can cause an immediate deadly reaction if the food isconsumed, food content (e.g. specific substances in food which caninduce a color change event if present), DNA or RNA, various geneproducts or genetically engineered substances, food oxidation state,freshness, temperatures that the food may have been raised to duringshipping and handling, whether certain foods have been irradiatedaccording to specific guidelines, and the like.

Diacetylenic and polydiacetylenic compounds may be produced in amultitude of forms or substituents for compatibility and functionalitywith foods, beverages and medications. The diacetylenic group may bemodified with lipid-like groups for solid phase or liquid phasecompatibility, carbohydrates, sugars, polar and apolar groups,functional groups such as amines, carboxylic acids, alcoholic groups,esters, amides, charge complexes, aliphatic groups, ethers, polyethers,amino acids, proteins, nucleic acids, mesogenic side chains, sulfhydrylgroups, block co-polymers and other groups which may be used to createspecifically desired characteristics. Compositions may be preparedhaving up to about 20 weight % of the polydiacetylenic polymer forcoating, which compositions further comprise carbohydrates, lipids orother physiologically acceptable composition.

The diacetylenic compounds or chromic agents present, whether monomersor polymers, in the composition added to the ingestible will generallybe present in at least 1 weight %, more usually at least about 5 weight%, and may be 75 weight % or more, usually being not more than about 60weight %.

Diacetylenic Monomer Chemistries:

Classes of photochromic, thermochromic, hydrochromic, lipochromic, andphysiochromic polymers can be made from a variety of organicdiacetylenic monomers including short chain molecules with no sidechains or substituents, short chain molecules containing one or morefunctional groups and aliphatic monomers that vary in length from 10carbon units to 50 or more carbon units with or without variousfunctional side chains or substituents. Molecules can be hydrophobic orhydrophilic depending on the desired application. They can be neutral orcharged in order to create a desired intermolecular or intramoleculareffect. The molecule can be non-polar, mono-polar, or multi-polar.Diacetylenic monomers can be symmetric or asymmetric. For food gradeapplications, the monomer and subsequent polymer molecules can containfood compatible groups including sugars, lipid chains, carbohydratemoieties, amino acids, peptides, proteins, complex proteins, effectorgroups, esters, alcoholic groups, amides, carboxamides, dextrans,heterocyclic substituents, acids, lipids, detachable nutrient groups,such as vitamins and nutraceuticals, catalytic groups such as enzymes,chelating groups, nucleotides, food colors, emulsifier groups, or thelike.

Side chains and substituents may be chemically modified for use with avariety of different foods. The hydrophobic or hydrophilic nature of thechemical compound can be adjusted to create compositions more or lesscompatible with fatty foods, carbohydrate-based foods, meats, dry foods,cereals, baked goods or the like.

The diacetylenic monomer will be a lipid mono- or dicarboxylic non-oxocarbonyl monomer or derivative thereof, so that acid, esters, or amidesmay be employed, a mono- or diol, ether or ester thereof, where the acidmay be organic or inorganic, e.g. phosphate, an amino or derivativethereof, where the derivative may be an organic substituent such as anacyl group, an aliphatic group, an aromatic group, a heterocyclic group,etc. The substituents at the termini will have from 0 to 30, moreusually 0 to 20 atoms, which will usually be carbon, oxygen, nitrogen,sulfur and phosphorous. The acid portion of the molecule (orunderivatized portion) will generally range from 5-30, more usually12-30, carbon atoms and the diacetylene groups which will be inconjugation, may be situated symmetrically or asymmetrically in themolecule. Thus, the flanking alkylene groups may be the same ordifferent in a molecule, where the temperature transition of the polymerwill depend upon the chain length of the monomer, whether thediacetylene groups are symmetrical or asymmetrical, and the degree ofdifference between the length of the flanking regions, whether one usesa single monomer to form a homopolymer or two or more monomers, usuallynot more than four monomers, to form a co-polymer, and whether thechains are substituted or unsubstituted, as well as the nature anddegree of substitution. Particularly, halogen substituents, e.g.fluorine, chlorine and bromine, may be present to enhance the uppertemperature limits possible with the subject compositions, ranging froma single substituent to persubstituted. The temperature range which isattainable using the various diacetylene monomers will range from about25-300° C., usually not exceeding 200° C., more usually from about25-200° C. For the purposes of this invention, the range of interestwill be from about 30-200° C., more usually from about 35-200° C., andparticularly from about 35-150° C.

For the most part, the diacetylene monomers will have the followingformula:

R(CH₂)_(n)(C≡C)₂(CH₂)_(m)Y  (1)

wherein:

Y is COX¹, amino (including substituted amino, e.g. alkyl substitutedamino of from about 1-6 carbon atoms), oxy having from 0 to 6 carbonatoms, thio of from 0 to 6 carbon atoms, cyano, halo, etc.;

m and n are at least 1 and total 8-25, preferably n is at least 2, morepreferably both m and n are at least 2;

R is H or Y; and

X and X′ may be the same or different, usually the same, may be any ofthe groups indicated above, generally being H, OH, OT, where T is offrom 1-8, usually 1-6 carbon atoms having from 0−(n−2) substituents,wherein n is the number of carbon atoms and the substituent may be oxy,amino, halo, thiol, etc, usually aliphatic, e.g. hydroxyalkyl, andaminoalkyl; or NT¹, T², wherein T¹ and T² are the same or different,usually the same and will have from 1-8, usually 1-6 carbon atoms, thetotal number of carbon atoms of T¹ and T² usually not being greater thanabout 6 and each having from 0−(n−2) substituents as described above,particularly oxy, one of T¹ and T² may be unsubstituted or substitutedamino(hydrazino), where the substituents will come within the definitionof T¹, polyalkyleneoxy, wherein alkylene is of from 2 to 3 carbon atomsand may have from 2 to 50 units; or two Y's may be taken together toform a divalent linking group of from about 2 to 2,000 daltons, whichwill usually be 2 T's taken together (T's include T and T¹). Monomerscan be used individually and in pure form. The position of theacetylenic groups may be symmetrical or asymmetrical in the molecule.

Of particular interest are monomers, such as 10,12-tricosadiynoic acid(C23) or 10,12-pentacosadiynoic acid (C25), which can be usedindependently during processing and production to achieve a lowersensitivity to ultraviolet irradiation (254 nm) or either compound maybe added in a percentage to the other to sensitize the mixture to makethe mixture far more sensitive to ultraviolet irradiation. 0.01-50% byweight of C25 can be added to C23 to make a mixture that polymerizes 50%or more quickly and achieves a much darker blue appearance afterpolymerization. More usually, 0.1 to 30% C25 is added to C23. Typically,1 to 20% C25 is added to C23. Formulation variations along withultraviolet irradiation times can be used to create differentthermochromic temperature settings. Combinations of formulations can beused to achieve a variety of visual effects upon temperature triggeringincluding patterns such as text, characters, images, symbols,trademarks, brand identity marks, messages, icons, logos, artisticdesigns or decorative designs. Patterns may appear to changenon-uniformly to create visual imagery such as the appearance ofmovement in a stationary picture.

The general structure of a diacetylenic monomer that is polymerized tobecome a polydiacetylenic chromic change agent consists of adiacetylenic unit with appending side chains on each end of thediacetylenic unit

The corresponding polydiacetylenic unit capable of undergoing a chromicchange is a continuous ene-yne structure with A(CH₂)_(n) and (CH₂)mBeach as side chains attached to an

individual ene-yne unit:

where Z represents the number of repeating units along thepolydiacetylene backbone. Z can range in number from 2 to greater than100,000. Usually Z will vary from 5 to 10,000. Typically Z will bebetween 10 and 1,000 units.

The number of methylene units n and m may be increased or decreaseddepending on the application of interest. Increasing the number ofmethylene units can have dramatically different effects on the resultingchromic triggering mechanisms. Altering the substituents A and B canhave the effect of sensitizing, tuning or optimizing a particularchromic triggering mechanism in the chromic change agent. The compositestructural features of an ingestible chromic change agent can be relatedto both the chromic change mechanism as well as the degree ofresponsiveness or non-responsiveness of the agent to a triggering event.Illustrative examples of chromic agent color change mechanisms andenabling structural features are summarized below but are not intendedto limit the scope of possible mechanisms or structural permutations.

Photochromic Agent Color Changes:

The primary enabling feature for a diacetylenic material to bephotopolymerizable such that exposure to ultraviolet light (254 nm)results in the formation of a color formation is the ordered crystalpacking state of the monomeric diacetylenic unit. A, B n, and m must bebalanced such that diacetylene crystals are aligned and can betopochemically polymerized. Typically A and B should be of a molecularsize and structure to promote and not inhibit crystal packing orsterically restrict the diacetylenic units from packing close enough toeach other in a crystal lattice as to restrict ene-yne bond formation tooccur between units. A and B can be similar or dissimilar in structure.A and n can be paired to comprise an alkyl chain and give the moleculefavorable hydrophobic-hydrophobic interactions for inducing good crystalpacking. B and m can comprise an identical alkyl chain to A and n togive the photochrome a wax-like characteristic. In contrast, m can bebetween 1 to 20 units while B can be a simple hydrophilic head groupsuch as an alcohol or amine. B can be more complex such as a carboxylicacid or amide linkage. Amine, amide, and carboxylic acid groups (B)paired with alkyl chains (A/n) make excellent ultraviolet photochromiccandidates.

Short chain lipid-like compounds, where n=3, A is a methyl group, m=3and B=COOH (see formula (3), above) form photochromic compounds thatturn red at room temperature when exposed to ultraviolet (254 nm) lightbetween 0° C. and 30° C. Long chain lipid-like compounds, where incombination n is between 4 and 20, A is a methyl group, m is between 2and 20 and B=COOH form photochromic compounds that turn blue whenexposed to ultraviolet light (254 nm) from as low as 0° C. to as high as100° C.

Symmetric compounds where the diacetylenic group is in a fatty acid formand is dimerized by bridging each fatty acid group through an amidelinkage with ethylene diamine or 1,4-diaminobutane make excellentcandidates for photochromic agents due to their facile crystallizationand polymerization characteristics.

Mechanochromic Agent Enabling Features:

Mechanochromic agents can be similar in structure to photochromicagents. A good crystalline matrix of the monomeric diacetylenic moietyis first formed followed by ultraviolet polymerization (254 nm). Formechanochromic triggering, it is desirable to start with a highlyordered blue polydiacetylenic polymer. Mechanical perturbationsubsequently changes the blue form of the polymer to the red form. Otherchromic changes such as conversion of the blue or red polymer form to ayellow form are also possible to achieve through intense and continuedperturbation. Since only a mechanical stress such as rubbing, sheering,compressing, or similar physical means is required to cause a chromicchange in the chromic agent and not a specific chemical reaction, themechanochromic molecular structure has few limitations.

The structure can be a simple alkyl chain, a fatty acid, an ester, anamide, a carbonate group, a thiol, an ether group, a polyethylene group,a sugar, a carbohydrate, an amino acid or a variety of other groups thatdo not adversely affect a mechanically induced triggering event. Theease of inducing a mechanochromic change is dictated by the selectedstructure. Rigid crystal structures with a high degree of structuralintegrity of the mechanochromic polymer require a higher level ofmechanical perturbation to induce a chromic change as compared withloosely packed crystal structures with weaker intermolecularinteractions. For example, 5,7-hexadecadiynoic acid (16 carbons inlength) requires little mechanical pressure to induce a chromic changein the polymer whereas 10,12-pentacosadiynoic acid (25 carbons inlength) requires several times more mechanical pressure to induce achromic change. Typically, the shorter the hydrocarbon chains (n and mless than 5) embedding the diacetylenic polymer the less mechanicalstress required to change its color. Weakly interactive head groups orside chains such as esters groups (B) can be used to reduce themechanical stress required to induce a chromic change whereas stronglyhydrogen bonding head groups such as multiple amides increase the amountof stress required to induce a change.

The degree of polymerization (Z) can play an important role in dictatingthe mechanical forces required to induce a chromic change. Shortrepeating units, caused from mild polymerization (e.g. where Z is 3-10units), can result in less required force needed to induce a change.Longer repeating units, caused by extensive ultraviolet polymerization,(e.g. where Z is from 50 to over 1,000), can result in requiringsignificantly greater forces to induce a chromic change.

Thermochromic Agent Enabling Features:

A primary feature dictating a thermally induced chromic change is themelting transition of side chains appended to the polydiacetylenicstructure. Similar to the mechanochromic example, shorter, more weaklyinteractive side chains typically require lower heat levels to induce achromic change. Longer, more strongly interactive side chains typicallyrequire higher heat levels. In the case of thermochromically inducedchanges, it is desirable to utilize side chain substituents mostaffected by temperature changes. Lipids, waxes and other hydrocarbonscan be used. In combination with side chain substituents, more stronglyor weakly functional groups may be used to adjust the thermochromictransition.

Ester groups, for example, exhibit weak intermolecular interactions andare useful in lowering the thermochromic transition temperature, whereasamides exhibit strong hydrogen bonding interactions between adjacentrepeating units and find use to raise the thermochromic transitiontemperature and facilitate a reversible thermochromic reaction. Sugarmolecules exhibit a high degree of intermolecular hydrogen bonding andcan be used to synthesize high temperature thermochromically reversibleingestibles (B) whereas polyethylene oxide substituents can be used assubstituents (B) to synthesize lower temperature irreversible compounds.Permutations of the hydrocarbon chain lengths (n and m) appending thediacetylenic unit can be used to fine-tune the desired temperaturechange setting.

The degree of polymerization (Z) also plays an important role indictating the temperature at which the chromic change will occur. Shortrepeating units, caused from mild ultraviolet polymerization (e.g.,where Z is 3-10 units), can result in lower thermochromic transitiontemperatures. Longer repeating units, caused by extensive ultravioletpolymerization, (e.g. where Z is from 50 to over 1,000), can result in asignificantly higher thermochromic transition temperature.

The compounds used to react with the carboxyl groups may be selected inrelation to the ingestible to be modified. Thus, the groups may bechosen to make the polyacetylenes more compatible with the ingestible,using polar compounds to enhance compatibility with polar ingestibles,non-polar compounds to make the polyacetylenes more compatible withlipid compounds, solubilizing groups which provide for solubility ordispersibility, and the like. Certain photochromic materials can undergoa second color transition upon high heat (greater than 200° F.) from ared color to a yellow color and then reverse colors upon cooling back toroom temperature. Among such materials are the dual chain glutamatediacetylene containing lipids. Mono-amide glutamate lipids and tri-amideglutamate lipids can be used alone or in combination to achieve similareffects at lower temperatures. For example, the molecule can be modifiedto have strong hydrogen bonding characteristics that cause strongintermolecular interactions between monomers along a polymer chain andexert a strong ordering characteristic along the chain. Strongintramolecular or interpolymer chain hydrogen bonding helps to stiffenand order the polymer backbone. Heading or perturbing the backbone causea stochastic conformational change along the polymer that results in acolor change from a highly ordered blue structure to a red disorderedstructure. Cooling or reversing conditions allows the intermolecular orintra-polymer chain hydrogen bonding interactions to dominate andre-order the polymer chain to an ordered blue structure. Among suchmaterials are single chain lipids containing one or more amides forpromoting intermolecular hydrogen bonding. For example, acetylatedethylene diamide-10,12-triconsdiyneoic amide contains two internal amidelinkages along a single chain compound. Alternatively, dual chain lipidscontaining a mono-, di- or triamide glutamate head group can be used. Inaddition carboxylic acid lipids where the diacetylenic back bone is inclose proximity with the head group (1-4 carbon atoms removed) have alarge influence over the polymer structure and can exhibit reversibility(e.g. 4,6-heptadecadiynoic acid) at moderate temperatures (68° F. to130° F.). Reversible thermochromic materials can be made using glutamicacid with two chains of 10,12-tricosadiynoic acid to form a dual chainglutamate lipid. Dual chain glutamate lipids exhibit a high degree ofthermochromic reversibility due the interlocking nature of themicrocrystalline structure and/or their hydrogen bondingcharacteristics. Generally there will be from 1 to 10, more usually fromabout 1 to 8 hydrogen forming groups in a repeating unit of the polymer,such as amide, hydroxy, keto, amino, etc.

A chemical/structural balance between carbon chain length, position ofthe diacetylenic group along the carbon chain, hydrogen bonding due tothe amide linkage, and head group structure can be achieved in thechromic change agent to give it characteristics of reversibility, foodcompatibility, processing ease, color change mechanism, stability, andother factors beneficial to use as an ingestible.

Diacetylenic forms of the chromic agent can be made into a hightemperature reversible material by creating a dual amide symmetriccompound where two long chain fatty acids (10,12-pentacosadiynoic acid)are bridged by an amide linkage by 1,4-butane diamine. The resultingmaterial forms a plastic/wax-like polymerizable material which remainsdark blue until it is heated above 150° C. Halogenating the even longerchain fatty acids along their methylene units can further raise thetriggering transition temperature to greater than 300° C.

Depending on the type of application, it may be desirable to have anirreversible thermochromic or physiochromic event or a reversible event.Hot liquids containing a reversible thermochromic material, for example,can be made to turn red at a high temperature and back to blue at someintermediate or room temperature. Upon reheating, the liquid would turnred again.

Cereals containing a low temperature reversible chromic material can bered at room temperature and change to blue upon addition of cold milk.An irreversible thermochromic material can be used to show a patternchange in a solid pastry indicating that the pastry was indeed heated toa certain temperature to reveal a message or picture which stays thesame even after cooling. Single chain monomers such as10,12-tricosadiynoic acid can be polymerized to form an irreversiblethermochromic property.

For lower temperature applications such as visualizing a color changewhen a food is brought to room temperature or above, it is desirable tohave a thermochromic compound which responds immediately to an ambientroom temperature. 10,12-tricosadiynoic acid or 10,12-pentacosadiynoicacid can be converted to the methyl ester form to create materials whichchange color from a deep dark blue to irreversible bright red, at about80° F. These can be useful for indicating that certain foods, whichshould be stored at less than room temperature, have been raised orheated to higher than room temperature. For example, in some cases suchas certain medications, dairy products or foods, it is desirable tostore them at room temperature or below and keep them from being raisedeven slightly above room temperature. In these cases, it may bedesirable to incorporate a thermochromic material, which tells consumersthat the product has at one time been held at an undesirably hightemperature and should no longer be consumed. It may be advantageous tohave the thermochromic material in direct contact with the consumablemedication or food and not with packaging, so that no false indicationsare made, and precluding expensive items from being disposed ofinappropriately. Shorter hydrocarbon chains attached to the diacetylenicbackbone can also be incorporated to reduce the energy or impactrequired to trigger a chromic transition. A balance between the hydrogenbonding, Van der Waals interactions, charge-charge interactions,hydrophobic-hydrophilic interactions, can be achieved to produce thedesired type and situation for color changing ingestibles.

Hydrogen bonding functional groups attached to monomers can be used toinfluence the chromic properties of corresponding polymers. Tightlyhydrogen-bonding groups can increase the energy required for the chromicmaterial to change color. Reducing the hydrogen bonding capabilities ofthe chromic material can be used to reduce the energy or degree ofchange in environment to cause a color change. Hydrogen-bonding groupsinclude polar atoms, such as oxygen and nitrogen, to which the hydrogenis bound. Hydrogen bonding can be structured between individual chromicmolecules or between chromic molecules and surrounding carrier materialswith which they are in association.

Of particular interest are thermochromically revisable monomers such asN-ethanol-hexadeca-5,7-diyneamide andN-propylamineeicosa-5,7-diyneamide. These compounds when polymerizedwith ultraviolet light (254 nm), become deeply magenta colored at roomtemperature. When the polymers are raised above room temperature theybecome red/orange and when they are chilled below room temperature, theybecome a deep purple/blue color. The thermochromic transition ofN-ethanol-hexadeca-5,7-diyneamide is approximately 5° C. lower thanN-propylamine-eicosa-5,7-diyneamide. The lower temperature triggeringtransition was achieved by using an ethanolamine head group rather thana propylamine head group and using a shorter 16 carbon chain rather thana longer 20 carbon chain. N-ethanol-hexadeca-5,7-diyneamide findsapplication to color changing cereals where at room temperature thecereal will appear magenta/red and turn blue when cold milk is added tothe cereal. N-propylamine-eicosa-5,7-diyneamide finds application tocoatings on cookies where at room temperature the cookie appears a darkmagenta. When the cookie is touched, raising its temperature above roomtemperature, the cookie appears red. When the cookie is dipped in coldmilk, the cookie appears dark blue/purple.

High-temperature reversible chromic agents find multiple uses bothindicators that foods have been raised above a safe cooking level (e.g.,one color will appear above 160° F.) and then subsequently as indicatorsthat foods have been cooled to a level that makes them safe to eatwithout burning tissue in the mouth (e.g., the original color willreappear near 110° F.).

Chemical changes such as these provide for wide range of latitude tomodify the chromic agent for a particular triggering range and productapplication. Food or other ingestible products often have discreterequirements such as shipping, storage, level of contaminants,acceptable moisture content or the like.

Irreversible color changes in polydiacetylenes can be introduced byeliminating or reducing the intermolecular or intra-polymer chainhydrogen bonding characteristics. For example, the polydiacetylenicmolecule can be a pure hydrocarbon structure without substituents, anester or have other relatively non-interactive groups. Additionally, thetriggering temperature can be dramatically reduced and made irreversibleby using short carbon chains such as 5,7-dodecadiynoic acid amidatedwith 2-(2-aminoethoxy)ethanol. The material is an oil at roomtemperature and will only polymerize at −10° C., where a blue polymercan be formed by ultraviolet irradiation (254 nm). Raising thetemperature above −10° C. causes the material to irreversibly turnred/orange. Materials such as these can find use in low temperature foodapplications.

Irreversible color changes are important to ingestibles containing themwhen it is desired to observe a color change at a certain temperaturelevel and it is desired to maintain “memory” of the temperature levelachieved at a given time or location. It is convenient to useirreversible thermochromic color change in polydiacetylenes during atemperature increase, converting the blue form of the color to a redform. For example, a thermochromic message can be revealed on a toasterpastry and the message is permanent until the pastry is ingested.

Extended triggering conditions can be achieved in polydiacetyleniccompounds by creating unique structures including attachment ofconstituent moieties such as sugars, amine acids or peptides, DNA orRNA, polyether groups, binding pairs, or organic groups which candominate the material's characteristics. Maximum temperature triggeringranges attainable can be extended to −30° C. or below to greater than350° C., usually not exceeding 300° C. and not below 25° C., and moreusually from between −20° C. to 250° C. For the purpose of thisinvention the range of interest will be from −15° C. to 225° C., andparticularly from −10° C. to 200° C.

Likewise, the substituents can be added to provide for other means todisrupt or order the polymer structure and thereby cause a reversible orirreversible color change in the polymer backbone, as described below.

Hydrochromic/Solvatochromic Agent Enabling Features:

An important feature dictating the hydrochromic/solvatochromic nature ofthe chromic agent is the ease of degree to which the material can beeffectively hydrated of solvated by a surrounding medium. The mechanismfor inducing a hydration or solvation change can be accomplished eitherby affecting individual substituent side chains or byhydrating/solvating complete layers adjacent to each other in thecrystalline lattice. As with other chromic change mechanisms, the easeor difficulty of inducing a chromic change can be dictated by theintegrity of crystal packing and the strength of intermolecular sidechain interactions.

Good hydrating side chain groups A and B include alcohols; polyetherssuch as polyethylene glycol terminated with an OH group, surfactantgroups or the like. Solvation-induced chromic changes, where polaraprotic solvents such as acetone are used as the triggering agent, areeffective when the side chain substituents are easily solvated withacetone. For example, n and m can be low in number (e.g. 1 to 3 units)and the head group can be a like kind substituent such as a ketone orester. Water-induced chromic changes are facilitated when both theintermolecular interactions between side chains and the intercrystallineinteractions between layers of the crystal lattice are affected bywater. It can be desirable to use symmetric compounds where A=B and n=mand both A and B are groups that are easily hydrated as well as groupswhich permit intercalation of water between layers in a crystal.

Mono- or multiple alcoholic groups can be introduced to promoteinteraction with hydrating or solvating solutions. Solvent orhydrochromic color changes are particularly attractive when combiningdry ingestibles with wet or moist ingestibles. For example, adding milkto cold cereal, dipping cookies or crackers in milk, adding crackers tosoup, pouring liquid syrups on breads or pancakes, adding saladdressings to salads, or the like, can be the trigger for a color change.

In addition, hydrochromic/solvatochromic effects can be used in uniqueways to propagate a color change along a surface. As hydration occursalong an absorbent layer and the moisture migrates, a blue form of thepolymer sensitive to solvation or hydration will turn the disordered redof the polymer to the ordered blue form. Messages or graphics can bevisualized sequentially to create time-resolved graphical changes.

Ethylene glycol or polyethylene glycol groups can be attached to themonomeric material to alter the solubility with different food types orhelp emulsify the monomeric chromic agent. Ethylene glycol linkers canrange from a single ethylene oxide unit to 50 units. More typically,ethylene glycol linkers range from 2 to 20 units and most convenientlyfrom 3 to 6 units. The number of units can be changed depending on thedesired level of hydrophobic or hydrophilic nature for the resultingmolecule.

Standard hydrochromic/solvatochromic indicating groups can be attachedin positions A and/or B to endow the base chromic change agent withmoisture-indicating properties.

pH Sensitive and Ionochromic Change Agent Enabling Features:

It is desirable to attach pH or ion sensitive substituent groups to thebase molecular structure such that a change in solution pH or ionicstrength in the surrounding medium can induce a chromic change in thepolydiacetylenic backbone. As with other chromic change mechanisms, theease or difficulty of inducing a chromic change can be dictated by theintegrity of crystal packing and the strength of intermolecular sidechain interactions. For example, groups that respond to ionic strengthsuch as a carboxylic acid can be used at positions A and/or B. It isdesirable to use shorter side chain lengths (e.g., n and m less than 4)in order to facilitate a higher degree of molecular mobility. Adicarboxylic acid where A and B are both COOH and n and m are both 1 to3 are of interest as ionochromic constituents since both ends of themolecule are affected during a triggering phase.

Groups susceptible to protonation or deprotonation or acid-basereactions are of particular interest. For example, A and/or B can be aprimary amine, secondary amine or the like. Changing the surroundingmedium from a neutral pH to an acidic pH can be used to cause a chromicchange in the medium. When A and/or B is an organic acid such as a monoor dicarboxylic form, treating the medium with a basic solution mayinduce a chromic change in the agent.

pH sensitive groups, e.g. bases and acids such as a hydrazide or a freeamine group, can be attached to the head group of a lipid or hydrocarbonmoiety to invoke a pH-triggering response from the blue form of thepolydiacetylenic polymer to a red form of the polydiacetylenic polymer.Ethylene glycol or polyethylene glycol groups can be attached to themonomeric material to alter the solubility with different food types orhelp emulsify the monomeric chromic agent.

Ethylene glycol linkers can range from a single ethylene oxide unit to50 units. More typically, ethylene glycol linkers range from 2 to 20units and most conveniently from 3 to 6 units. The number of units canbe changed depending on the desired level of hydrophobic or hydrophilicnature for the resulting molecule.

Standard pH-indicating groups can be attached in positions A and/or B.Indicators specific to a particular pH unit are of interest since theymay find use as ingestibles to monitor saliva pH. Ionophore-sensitivegroups can be attached in position A and/or B to endow the base chromicchange agent with ion-selective properties.

Chemochromic and Biochromic Agent Enabling Features:

It is desirable to attach chemically or biochemically sensitive and/orselective groups to A and/or B to give the chromic agent specificity tocertain chemical constituents in an ingestible matrix. As with otherchromic change mechanisms, the ease or difficulty of inducing a chromicchange can be dictated by the integrity of crystal packing and thestrength of intermolecular side chain interactions.

Examples of chemically selective groups can include caged compounds,chelating compounds, crown ether groups, peptides, DNA or RNA fragments,transition state analogs, binding pair members, or the like. Groups Aand/or B can be more or less selective depending on the ingestibleapplication. The chromic agent can be made more or less sensitive tochemical or biochemical triggering by increasing or decreasing n and m,respectively; shorter chain lengths typically require of lowerconcentrations of the chemical or biochemical to induce a chromicchange, whereas longer chain lengths generally require higherconcentrations of the chemical or biochemical required to induce achromic change.

Formulations and Compositions:

Monomeric or polymeric chromic change materials can be combined with acarrier material to form a composition which makes it possible for it tobe applied to and/or adhered to foods. Carrier materials can range froma simple aqueous solution to complex mixtures containing differentemulsifiers, flavors, or foodstuff. Constituents such as oils, lipids,waxes, sugars, salts, lectins, agglutinins, protein matrices,carbohydrate matrices or the like can be combined alone or together withan unpolymerized agent or polymerized agent to give the agent theproperties necessary for transfer to, adherence with, or stability on afood type.

Carrier materials suitable for printing can include aqueous solutions orpastes, which are applied and dried more slowly. Alternatively, thesolution can contain an ethanol base, which can be dried more quickly.The carrier for printing can contain any food compatible composition.

Carrier materials suitable for extrusion can contain thickeningsubstances to give it the consistency for rapid extrusion and patternformation on the food surface of interest. Starches, methylcellulose,but pastes, dextrins, polydextrins, protein pastes, sugars, driedgelatins, rice papers, doughs, frostings, sugar-based papers, edibleinks, edible waxes, ingestible polymer substrates, caramelized sugars,or the like can be used for a support surface to which the chromic agentcan be applied. Thickened carriers provide for the ability to form threedimensional structures such as overlaying lines or patterns, that canenhance the contrast for the thermochromic or physiochromic colortransition. Carriers suitable for lamination can include substances thatprovide for stable layers to be applied to the food of interest.

Binding agents can be used to integrate more or less of the chromicmaterial with a particular food type. In most cases, it is desirable tobind the chromic material tightly to the food so that the material staysvisibly in contact with the particular part of the food portion it isinitially on and that the material does not slough off into asurrounding liquid or rub off on any packaging materials. Binding agentscan include sugars, carbohydrates, proteins, methyl cellulose, and othermaterials commonly used to bind food colors, coatings, frostings,sprinkles and the like. The binding agent can be co-mixed with thechromic material, coated after application of the chromic material toform a protective layer, or used in combination with both the food andthe chromic material.

Various traditional, inactive ingredients can be used to co-mix,pre-color or adhere the chromic agent to a support surface on theconsumable product including: hydroxypropyl cellulose, hydroxypropylmethyl cellulose, microcrystalline cellulose, starch, red iron oxide,magnesium stearate, titanium dioxide, talc, colloidal silicon dioxide,polyethylene glycol, various synthetic polymers, Yellow 10 dye, carnaubawax, corn starch, sodium starch glucolate, or the like. These variousadditives are conventional and will be present, when employed, in arange of from about 0.1 to 95 weight %.

Configurations of Application for Chewable Foods:

The chromic material, such as diacetylenes, need to be in amicrocrystalline phase in order to polymerize to the chromic material.Therefore, if the diacetylenes are to be mixed with other componentsthat adversely affect the formation of the microcrystalline phase, thediacetylenes will normally be prepolymerized before formulation.Solution phase chromic material or monomer can be applied to a chewablefood surface, dried and then polymerized. Liquid phase monomer can bepolymerized if in a colloidal/crystalline form, applied to a solid foodsurface, and dried. Solid microcrystalline monomer can be admixed withfood carriers, applied to a solid food surface, and then polymerized.Solid microcrystalline monomer can be first admixed with a food carrier,polymerized, and then applied to a food surface. Solid microcrystallinemonomer can be first polymerized, admixed with a food carrier, and thenapplied to a food surface.

The solid surface of the food may be processed to accept the monomer orchromic material. In many cases, if the food surface is too porous themonomer or chromic material will dissipate into the interstitial spacesbelow the surface, rendering it unavailable for visualization. Solidfood surfaces can be prepared for accepting the monomer or chromicmaterial by modification of the food composition or coating the surfacewith a composition, which seals the food surface. In either case,application of the monomer or chromic material to the food surface willprovide for a means to keep the material on the surface and visible.Illustrative of such situations are sugars, proteins, digestiblecelluloses, methylcellulose, polydextrins, digestible waxes and gums,which can also be used to create a smooth hydrophobic barrier for evencoating of the physiochromic agent.

Structures containing the physiochromic agent can be created which comein contact with the food type of interest. The structures themselves canbe compatible with food and can be made with digestible components orcan be made of material that is certified for contact with food but notmeant for consumption. Structures can be labels, part of the package, aninsert in the package, paper rings, tabs or the like. The structures canbe printed with the physiochromic material in a way in which thestructure can interact with the food. For example, the structure can bean adherent label containing a thermochromic form of the agent. Theadherent label can be adhered to a food type meant for heating. When thefood is heated, the thermochromic agent will change color. If the labelstructure is edible, it can remain in contact with the food type and beconsumed along with the food. If the structure is safe for food contactbut not edible, it can be part of a packaging material or removed priorto consumption.

The monomeric or polymeric form of the chromic agent can be fused oradmixed into foods or medications. For example, a polymerized liposomalor colloidal form of polydiacetylenic material can be processed withgelatin to produce a thermochromic form of desert gelatin. Atrefrigerator temperatures (40° F.), the gelatin could appear dark blue.When raised to room temperature (68° F.), the gelatin would turn brightred/orange. Alternatively, a polymeric chromic agent could be cast intoa throat lozenge. A chromic agent that undergoes a temperaturetransition from dark blue to red/orange at 100° F. could be employed tohelp a consumer determine if they have a fever. Usage of the lozengewould indicate to the consumer that they have a low grade fever if thelozenge turns red/orange. The consumer could also examine his tongue tosee if either a red or a blue color has come off the lozenge. Blue wouldindicate no fever and red/orange would indicate a low-grade fever.Similarly, chromic change agents can be incorporated in tablets, pillsor other medications formulated to be taken by a sick patient, and canindicate the presence of a fever by a color change, which remains withor comes off the medication.

The thermochromic material can be patterned alone or in combination withfood-based inks to create bar codes. Bar codes can be utilized inconnection with cooking where the cooking system, equipped with a barcode scanner, can measure a change in the bar code as the code isexposed to high temperatures. Bars on the code can be made to changecolor when one or more temperatures are achieved. The optical densitychange in a given bar will result in a prescribed change and interpretedby the measuring system to indicate a specific temperature. The bar codecan indicate doneness or in process cooking. The bar code can be printeddirectly on the solid food type or on the food packaging. This allowsthe bar code and bar code reader to be used as a temperature measuredevice.

Methods for Triggering Color Change:

The chromic change can be tailored to match a desired effect or outcomein a particular food or ingestible. Color change triggering processescan include temperature, pH changes, changes in ionic strength,mechanical changes such as stress or pressure during mixing orcontortion, chemical changes such as the addition of a second component,exposure to light for a photochromic effect, biochemical reactions suchas binding pair interaction, solvent environment changes, hydration ordehydration, solvent changes, and enzymatic changes where enzymes in thefood can induce a change. The methyl or ethyl ester of10,12-tricosadiynoic acid or 10,12-pentacosadiynoic acid is made bystandard esterification in methanol or ethanol respectively. The estercompound can be applied to foodstuffs, crystallized and then polymerizedat or below room temperature.

Physiologic changes in pH, ionic strength, or hydrogen bonding agentscan be used to alter the state of the chromic material, which may beinduced by finger touch or contact with saliva. Saliva is relativelyacidic and can be used to induce an acidic environment which can cause achromic change in foods containing the chromic material. The darkchromic material is extremely sensitive to thermal contact and changescolor immediately at 70° F. for the tricosadiynoate ester and at 80° F.or above for the pentacosadiynoate ester. The chromic material can besensitized to respond to physiologic temperatures (i.e., about 98° F.for humans).

Physiochromic matrices can be formulated to hold the chromic agent inone state until the matrix is dissolved. Once the matrix is dissolvedand its effect on holding the chromic agent in one state, the chromicagent is free to change conformation to another state. For example, anacid sensitive, pH reversible physiochromic agent can be dried down withan acid. The acidity can hold the polymer in one colored state. Thelocal concentration of acid is high in the dry state. When a physiologicbuffered solution is added, the acid is released and neutralized by thebuffer. The physiochromic agent can now covert to an alternative colorsince it is bathed in a basic environment.

Combination colors can be integrated along with the chromic material tocreate a variety of color change effects. For example, the brown colorused in a variety of food types is made with a combination of yellow,red and blue. The blue food color can be replaced with a blue form ofthe chromic agent. Upon color change triggering, the brown food colorcombination can be converted to a bright red-orange. Examples of browncolored foods or beverages include brownie mixes, hot and cold chocolatedrinks, cinnamon colors, and the like.

The physical, conformational, or polymerization state change can be usedas a mechanism to release or change certain embedded flavors, nutrients,aromatic compounds, nutraceutical agents or the like. For example, aflavor material can be chemically coupled to a monomer non-chromic formcompound. In the monomeric form the compound-flavoring expresses aflavor, whereas upon polymerization the monomer becomes polymerized,consequently restricting the flavoring to interact with taste receptors.The restricted form of the flavoring becomes non-flavored. The releasemechanism is simultaneously traced with a physiochromic color change asan indicator.

Alternatively, conformational changes in the chromic material matrix canbe utilized to release various food grade compounds. For example,polydiacetylene in its blue form is highly ordered on the molecularlevel. During processing and polymerization, a food grade compound suchas a vitamin or flavor can be trapped. Upon temperature or physiochromictriggering of the polydiacetylenic material to the red form, thepolydiacetylene becomes disordered and opens at various positions.During the conformational disordering of the polymer, the vitamin orflavor can be released. The monomeric form of the chromic material canbe used to absorb and allow in the flavor or aroma. Polymerization couldbe used to trap in the flavor or aroma. The ordered blue form of thepolymer may hold a flavor or aroma where heating results in aconformational change and disorder in the polymer which is useful torelease the flavor or aroma.

Specific physiochromic changes may be desirable when developing foodsthat a producer would like to differentiate from a competitors. Bindingmoieties can be used to facilitate specific photochromic, thermochromic,or physiochromic color transitions. Lectin-receptor agglutinin-receptor,antibody-antigen, biotin-avidin interactions or the like can be used tostimulate a binding pair interaction between different food components.Binding pair interactions can be used to create specific colorimeterchanges in the chromic agent. For example, a combination of milk andcereal can be formulated in which a specific type of milk contains onemember of a binding pair, such as a multiple biotinylated milk proteinand the cereal contains a biologically active form of the physiochromicagent that contains avidin or streptavidin as a second member of thebinding pair. When the specific milk comes in contact with the specificcereal, then only that milk will cause the specific cereal to changecolor through the binding interactions of the binding pair members. Noother milk or cereal combinations could cause a chromic change withoutthe selective interactions of those binding pair members. This scenariocan help food manufacturers create novel means of brand differentiation.

Carbonation pressure release in opening sealed carbonated beverages maybe used to induce a local stress/concentration change, which could causea color triggering changes in the chromic material. For example, theinside of a liquid container can be coated with a pH or frictionsensitive version of the physiochromic material. Upon opening thecontainer and release of built up pressure to ambient conditions, theprocess of bubble nucleation and local carbonic acid concentrationchange may be used to cause a change from environmentalcondition/conformation of the color change agent to another form of thematerial. If the container is clear, the color change can be madeevident to the observer of the color change. The color change agent caneither be in a water solution form such as contained within a liposomestructure or be coated on the inner wall of the container.

For hydration-activated color change, physiochromic agents which changecolor depending on the degree of solvation or hydration can be used(hydrochromic agents). Color change agents capable of changing colorupon partial or complete hydration and can be ingestible can findmultiple uses for food or food related products. For example, thebi-polar diacetylenic compound 4,6-decadiyne-1,10-diol when adhered to asurface and polymerized at room temperature forms a deep blue/purplepolymer. The blue/purple polymeric form of the material changes to ared/orange color upon hydration below or above the melting transition ofthe material. One mechanism for inducing the color change may be rapidintercalation of water between the layers of the crystalline latticewhere the aqueous phase disrupts the ordered polymer lattice.

The hydrochromic agent's rate of color change is temperature andconfiguration dependent. For example, the rate of color change from theblue/purple color to a red/orange color is rapid and occurs within aminute when a thin layer of the hydrochromic agent is uniformly spreadover a dry porous structure and exposed to an aqueous fluid at or 10° F.below the melting transition of the material. The color change is slowedsignificantly from one to several hours if the hydrochromic agent isapplied in a thick layer (0.1 to 1.0 mm) and treated with an aqueoussolution near freezing.

The hydrochromic agent can be placed on an ancillary material such ascarbohydrates, granulated sugar, sugar sprinkles, fondant, sugar pastes,candies, nutritional bits, food coatings, condiments, carriers,emulsifiers, coating materials or the like and subsequently applied to afood surface. For example, the diacetylenic compound4,6-decadiyne-1,10-diol can be conveniently dissolved in an alcoholicsolution (0.15 g/ml) and the solution applied to white or colored sugarsprinkles. Upon coating, drying and polymerization, the sugar sprinklescan subsequently be adhered to a cookie, cereal, candy, bread, cake orthe like. The dark blue/purple sprinkle changes to an orange/red colorimmediately upon treatment with water, milk or other liquids capable ofdisrupting the crystal packing of the chromic agent.

The use of hydrochromic agent pre-coated sugars, salts or other carriershas the advantage of providing a high degree of coloration and surfacearea for fluid contact. For example, a fine hydrochromic/sugar particlecoating creates capillary channels for fluid to wick through, therebyfacilitating the hydration process.

Other structures may also conveniently contain the hydrochromic agentplacing it in close or intimate contact with foods. For example, thematerial can be placed on a bowl, spoon, plate, fork, straws, ahydrating strip, a package insert, part of the package or the like, suchthat a portion of an absorbent material can be in liquid contact with aningestible liquid. As the liquid hydrates the structure, the liquidsolvent hydrates and migrates along the structure causing thephysiochromic agent to change color. If the structure containing theagent is edible, it can remain in contact with the ingestible liquid andbe consumed. If the structure containing the agent is safe for contactwith food, but inedible, the structure can be removed prior toconsumption of the ingestible liquid.

Mechanical/frictional means can be used to induce color changes in avariety of food compatible products. Color changes can be induced usingmechanical means primarily including friction due to rubbing,elasticity, and shearing. For visible friction-induced color changes,the color change agent can be permeated into or placed on a surface.Rubbing, stretching, and shearing or other stress-causing action alsocan be used to induce a frictional force on the color change agentresulting in localized heating. The ease and magnitude of color changeis dependent on the transition temperature of the chromic agent, thefriction coefficient between the molecules in the composite or a rubbingtool and the thermal insulative/conductive properties of the compositeor rubbing tool. Rubbing tools can include a person's fingers, fingernails, teeth, a wooden stick, a plastic implement or the like. Materialsthat are more thermally insulative may result in more thermal energyremaining with the chromic agent and less being transferred to thecomposite or rubbing tool. Metal rubbing tools serve as poor devices forinducing a frictional color change, whereas insulative materials such asplastic or wood provide an easier means for inducing a color change.

Mechanical/frictional color change methods are attractive for revealingmessages, altering graphics, introducing codes, creating sweepstakes,creating entertaining graphics or the like.

Touching, rubbing mixing, chewing, kneading and various other forms ofhandling can be used to induce the color change. The color change agentmust be responsive to the available amount of frictional forces. Theagent must also be stable to ambient temperatures and humidityconditions or a color change may result from influences other thanfrictional/mechanical forces. An exemplary compound, the blue polymericform of 10,12-octadecadiynoic acid exhibits good thermal stability up to100° F. with full hydration, whereas rubbing the dry form of the bluepolymer easily triggers the polymer to the red form of the polymer.

Mechanical/frictional triggering can be performed directly on a foodsurface, on a laminate in contact with the food or on a generic surface.In each case, the triggering process can be used to reveal hiddenmessages, illuminate branding messages, provide a means of interactivegraphical changes or the like.

The mechanochromic material can be applied to a surface by a variety ofmeans including application of a solvent containing the chromic agent bymeans of ink jet printing, spraying offset printing processes, blotting,pad printing, dipping or soaking. Concentrations of the chromic agentcan be from about 2 g/ml to 0.01 g/ml, typically in the range of fromabout 1 g/ml to 0.05 g/ml, usually from about 0.5 g/ml to 0.1 g/ml.Alternatively, the chromic agent can be applied using transfer methodssuch as thermal transfer, rubbing from a solid, from a molten liquid orthe like.

Photoactivation can be used to cause color changes in foods orfood-related products when an appropriate photochromic agent isintroduced. Convenience foods containing a photochromic agent whenplaced in sunlight provide an entertaining means to create a variety ofeffects. For example, cookies, cereals and various other conveniencefoods can be used to reveal, various logos, branding identities, codes,sweepstakes information, messages or co-merchandising items to theconsumer.

The photochromic agent can be patterned on or applied to the food,packaging material or implement in contact with the food by meansdisclosed earlier. Photochromic agents have the advantage of notrequiring incidental heat of fluids to create a visual effect. Dependingon the photochromic agent, the food can either turn from a natural foodcolor to a new hue or from a given hue to an alternate hue.

For thermochromic agents, temperature ranges can include coldtemperature for frozen and then thawing (−20° F. to above 32° F.), lowtemperatures from refrigerator levels to room temperature (33° F. to 60°F.), moderate room temperatures to moderately above room temperature andoverlapping temperatures from (61° F. to 100° F.), and room temperatureto moderate to high cooking temperatures (70° F. up to 200° F.). Thefinal temperature triggering range for the chromic agent is dictated bythe hydrocarbon chain length of the molecule, the intermolecularhydrogen bonding capabilities of the molecule's head group, additionalside chains of moieties which influence intermolecular attractions orrepulsions or the like, environmental effectors which impact the finaltemperature triggering transition for the chromic agent, and the degreeof polymerization to which the chromic material is exposed. Guidelinescan be given, but for a particular transition temperature change, theactual change must be determined experimentally. One can try differentamounts of the effectors and graph the effect of the concentration ofeffectors with the change in transition temperature. A curve is producedwhich allows the determination of the amount of effector, with thechange in transition temperature.

Environmental effectors combined with chromic agent to increase ordecrease the thermochromic transition of a given thermochromic agentinclude: various oils, waxes, low levels of organic solvents such asalcohols, ketones, ethers, chloro- and fluorocarbons, metal ions andother ionic compounds, chelating compounds, emulsifiers, or the like.The effector material can change thermochromic transition by alteringthe energy required to induce a thermochromic transition in the agent.Oils and organic solvents can interact with the long chain hydrocarbonsof a C23 or C25 polydiacetylenic acid. The chain packing can bedisrupted by the effector to create a metastable state in the polymerthat can, in turn, change color at a lower temperature. For example, thetemperature transition can be lowered for a polymerized C25polydiacetylene polymer in its native dry crystalline state from atemperature range of 150° F.-170° F. (depending on the degree ofpolymerization) down to 120° F.-130° F. by suspending the crystals in asugar syrup and adding trace amounts of ethanol. Concentrations of oilsor solvents added to a matrix can be from 0.001% to 100%, based on 100%of diyine, more usually from 0.01% to 50%, and typically from 1% to 10%.

The melting transition of the wax or oil in contact with the chromicagent can directly increase or decrease the intrinsic transitiontemperature of the chromic agent. Oils that solidify under freezingtemperatures can stabilize the chromic agent. Upon a temperatureincrease above melting transition temperature of the oil or wax, themelting process can facilitate the melting of a hydrocarbon side chainon the chromic agent, causing it to undergo a thermochromic transition.The final thermochromic agent triggering temperature can be furtheradjusted by selecting a specific temperature at which polymerization ofthe chromic agent is performed. Polymerization at subzero temperatures(−10° F.) lowers the final triggering temperature relative topolymerization at temperatures just above freezing (10° F.).Thermochromic transition temperatures can be increased by increasingintermolecular stability, such as promoting hydrogen bonding ofhydrophobic interactions, both between monomeric units within a giventhermochromic polymer chain and between the polymer chain and a giveneffector molecule. For example, the transition triggering temperature ofa C23 or C25 polydiacetylenic acid polymer can be increased by embeddingthe polymer in a high temperature-melting paraffin or wax. Thethermochromic material can be embedded in waxes from a concentration of0.01% to 99%. More usually from 0.1% to 50% and typically from 1% to10%.

Alternative Chromic Agent Triggering Mechanisms and Color ReportingProcesses:

Alternative triggering mechanisms include the use of enzymes orpre-digestive effectors primarily from saliva which can chemically orbiochemically induce a color change in the chromic agent through acatalytic change. For example, enzymes responsible for the initialstages of starch break down occur in saliva. Chromic agents chemicallymodified with starch or carbohydrate chemistries can be made susceptibleto enzymatic activity resulting in a conformational or environmentalchange which in turn can cause a color change in the chromic agent.

Microbial metabolites, enzymes, or by-products find use as a triggeringmechanism for the chromic agent resulting in a means to detect certainbacteria in foods. For example, the chromic agent can be chemicallymodified to respond to certain by-products produced by Salmonella. Thechromic agent is placed near or coated on the inner surface of a wrapthat is in contact with a processed chicken carcass. If Salmonella ispresent in the carcass and produces a triggering compound the chromicagent is triggered, indicating the presence of Salmonella.

An alternative mechanism for microbial detection is the use of a themicrobial cell's uptake of monomer forms of the chromic agent. Forexample, E. coli can use diacetylenic fatty acids as a carbon source.Incorporation of the polymerizable acid into a bacterial cell membranecan be detected by ultraviolet irradiation of the bacteria resulting inpolymerization of the acid to a blue color. Food processors can simplyirradiate food; development of blue color indicates the presence ofharmful bacteria.

Importantly, polydiacetylenic materials as a class of intrinsic chromicchange agents can be selectively tuned to respond to specific triggeringprocesses relevant to ingestible products. Additionally,polydiacetylenic materials can uniquely undergo multiple differentsequential color changes. Examples include photochromic triggeringfollowed by irreversible thermochromic triggering; photochromictriggering followed by reversible thermochromic triggering; photochromictriggering followed by mechanochromic triggering; reversiblethermochromic triggering followed by irreversible chemochromictriggering; multiple thermochromic transitions during increasing ordecreasing temperature exposure; and other permutations.

Configurations for Liquids:

Liquid phase monomers can be included in an unpolymerized form in abeverage or consumable fluid, such as in a syrup where the monomer is ina colloidal or microcrystalline state. The monomer can be directlypolymerized with an ultraviolet light source or sunlight. The solutionsuspension monomer can also be pre-polymerized and then added to aliquid phase consumable. The monomer can be made water-soluble usingshort chain compounds, which are mono- or bi-polar. In this case, themonomer must be prepolymerized in a solid form and then solubilizedafter polymerization. Polydiacetylenes undergo a topochemicalpolymerization and must be in a crystalline state in order forpolymerization to occur. Monomeric lipophilic forms of diacetyleniccompounds can form colloidal particles, such as liposomes, vesicles, orother lamellar forms. Lipophilic forms of the monomer can becrystallized in a colloidal state and polymerized while the monomer issuspended in an aqueous solution. Colloidial or microcrystallinesuspensions of monomeric diacetylene can be made using ultrasonicationor standard reverse phase vesicle formation methods. Heating and coolingcycles along with intense sonication can be useful for improvinguniformity and homogeneity of the suspensions.

For alcoholic beverages, the monomer can be processed into the beveragesusing reverse phase vesicle formation. The monomer can be dissolved inethanol and combined with the beverage aqueous constituents. Vesicleformation can be accomplished using standard processes. After thebeverage has been formulated, polymerization of the monomer can beaccomplished using standard polymerization methods.

Methods for Application to Foods:

Compositions containing either pre-polymerized material or monomermaterial can be processed into foods using a variety of applicationmethods such as ink jet printing, pad printing, extrusion, spraying,liquid applicators, dip coating, sublimation, spreading, application oflaminates containing the material such as sugar layers or rice paper,edible labels, dripping, dye sublimation printing or the like. Themethod of interest will depend on the food substrate utilized, thecomposition to be applied and the desired format in which thecomposition is to be placed.

Coating Matrices and coating methods for sugars, salts, shredded andpowdered cheese, flower, grains, nonpareils, and other powdered forms offoods. Polyethylene glycol coating matrices for cereals and cookies arepractical due to the unique solubility properties of polyethylene glycolpolymers.

Co-coating matrices can have the combine properties of helping to adherethe chromic agent to a food type, suspending the chromic agent in amatrix to maximize the visual appearance of the chromic agent, helpingto modulate the activity and performance of the chromic agent, helpingto minimize the amount of chromic agent required, and the like. Forexample, the coating matrix can have the property of allowing thechromic agent to undergo a conformational transition from one color toanother by providing the necessary flexibility required by the chromicagent.

The coating matrix can also provide a source of inducing defectstructures in the solid phase of the chromic agent or as a means forintroducing doping agents along with the chromic agent as enhancers toimprove the agent's optical performance. Doping agents can be used toenhance the optical properties of irreversible and reversible chromicagent changes. Low levels of additives can be used to enhance thecolorimetric changes that the material can undergo. Doping materials caninclude chemically/structurally related compounds which help create amolecular environment favorable to the transitions necessary for thechromic agent to undergo changes during its transition from one color toanother.

The coating matrix can also help provide a protective barrier for thechromic agent by minimizing the unwanted effects due to oxidation,moisture, or stabilization of the chromic agent of effectors of thechromic agent during storage and shipment of the final end product tothe consumer or during product production.

Coating matrix solutions can be made using a variety of solventsincluding polar protic solvents such as water ethanol and methanol,apolar organic solvents such as dichloromethane, polar aprotic solventssuch as acetone, or the like. It is desirable to use solvents that areconsidered food grade such as non-denatured ethanol.

For application to cereals, it is desirable to place the photochromic,thermochromic, or physiochromic material in a carrier material such as asugar matrix whereby the matrix is applied as a coating to the cerealduring production. For application to convenience foods such as flatpastries or cookies where patterning is important, high-speed printingtechniques are important. In this case it is desirable to use a solubleform of the material so that it can be incorporated directly into theliquid matrix used for printing.

The monomer or polymeric material can be applied to a solid food using alaminate overlay where the base material in the overlay/laminate isitself edible and contains the monomeric or polymeric color changematerial. Rice paper can be used as a laminating material which whenwetted and containing the polymer can be easily adhered to the food as asubstrate. Laminates can contain the chromic agent in combination withsugars, carbohydrates, digestible polysugars, or proteins, which givethe laminate a stable layer. The layer can have the property of beingdirectly layered on to a food surface, fused and then activated forphotochromic, thermochromic or physiochromic activity. Food laminatescapable of containing the chromic material can be any commerciallyavailable product or formulation that is physiologically acceptable andcan be printed or coated. For example, the laminate can be a marzipansheet available through most bakery supply sources. The thin sheet canbe printed, stamped, blotted with the chromic material by any convenientmeans, dried and polymerized. The laminate can then be adhered to thefood type surface alone or with food pastes.

Commercially-available laminate/paper materials compatible with ink jetprinting can be used (Kopykake, Torrance, Calif.).Commercially-available ink jets can be modified to contain an inkversion of the chromic agent. The ink jet cartridge can be used with anaqueous or solvent-based solution containing the chromic agent. The foodgrade laminate/paper can be inserted into the ink jet printer andstandard ink graphics printing programs utilized to generate text andgraphics. The laminate approach provides a means for generatinghigh-resolution graphics and text and transferring the images or textdirectly to the food type. The laminate can be made to be compatiblewith the food flavor and texture. For example, it is desirable to have asugar-based laminate for sweet products such as pastries, cookies, andcertain convenience foods. Alternatively, it is desirable to have asalt/seasoning-flavored laminate for dairy or processed meat products.The exact composition, flavor, and texture of the laminate will dependon the food component into which the chromic material is integrated.Laminates have the advantage of being separately prepared from the foodproduct and then processed to be a part of the food. Parallel processingprovides for high-speed production and simplified implementation.

Edible food grade labels, paper or wrappers containing the chromicmaterial can be used for a wide range of general applications. The labelcan be made with a digestible carbohydrate material rather than anon-digestible cellulosic material. Printing the chromic material can beaccomplished by standard printing means. The printed chromic label canbe applied to any solid and reasonably flat surface such as a cookie, atoaster pastry, baked goods, and a variety of convenience foods. A majoradvantage to chromic labels is that they can be pre-mass produced andsubsequently applied to finished foods rather than requiring changes inexisting food production processes. The chromic material can madesoluble in ethanol or various highly volatile solvents, which can bequickly evaporated, or in an aqueous solution, which can be absorbed. Inany case, it is desirable to coat the surface of the food substrate withthe chromic material so that upon polymerization the chromic material ishighly visible. The substrate can be dipped into a solution containingthe chromic agent, thereby coating the agent on the substrate's surface.

Entertainment foods such as marshmallows can incorporate the chromicmaterial using dip coating or spraying processes to provide an extralevel of enjoyment, especially for children. Chromic marshmallows can beproduced to respond to ambient temperatures such as touch or elevatedtemperature fluids, like hot chocolate. Marshmallows can be directly dipcoated with a higher temperature thermochromic material dissolved in analcoholic solution. After drying and polymerization to produce the darkcolored chromic agent, the marshmallows would remain dark until exposureto high temperatures such as an open flame. Upon exposure to anyelevated temperature, the dark marshmallow would turn bright orange-red.

Alternative means of incorporating the chromic agent into foods couldinclude biochemical substitution. Fruits, vegetables, certain meats,bacterial cultured dairy products such as yogurt, grains, rice, beans orother amenable foods can be grown with the precursor monomeric materialas a nutrient for the growing food. Upon incorporation or biochemicaluptake of the precursor monomer through the appropriate pathway into thefood product, the food can be irradiated with ultraviolet (254 nm) tocause polymerization of the foodstuff. Various dairy products such ascheeses, milks, and yogurts that naturally contain bacterial cultures toaid in digestion can be made with monomeric and/or polymeric chromicagents.

Spectral Colors Relating to Chromic Change Agents:

The color, contrast, and hue can be adjusted to give a chromic changeagent particular visual characteristics. Color change characteristicscan be achieved by changes in the chromic agent itself or in combinationwith stationary base colors associated with the same matrix as thechromic change agent. Various permutations of base colors in combinationwith the initial color of the chromic change agent will give one visualcolor to start with and often an unexpected color with which to finish.Chromic change agents with chromically reversible properties can be usedto achieve repetitive visual effects compared to irreversible chromicchange agents that can be used to achieve a one time effect.

Standard Pantone Colors, RGB, CMYK and colors typically used in the foodindustry can be used in combination with the chromic change agent.Examples of color change options based on the change of the chromicagent alone (white or clear base color) or in combination with a otherbase colors listed below but are not limited to any specific example areshown in Table 1.

In addition, color additives such metallic flakes, glitters, sparkles,and other elements which augment colors, can be used to create desirablevisual effects. For example, silver coated non-pareils can be coatedwith a red reversible form of the chromic change agent to give theeffect of a shiny red anodized sphere. When the combination is cooled,the coated non-peril appears to have a dark blue metallic anodizedcoating.

TABLE 1 Color change options based on initial chromic color and basecolor. Initial Chromic Starting Triggered Color Base Color CombinationColor light blue white/clear light blue pink medium blue white/clearmedium blue orange dark blue white/clear dark blue red/orange magentawhite/clear magenta red magenta white/clear magenta blue red white/clearred blue red white/clear red yellow yellow white/clear yellow red blueyellow green orange pink yellow magenta green red yellow orange brownorange orange dark orange dark brown orange light blue purple dark blueorange light green red/green gray green orange pink red purple red tandeep red blue/purple light blue light green gray green red/green yellowred orange red yellow light tan golden brown red light blue brown orangered light green brown navy blue

Food grade metallic and pastel colorants (Linton Paper & Supply, Inc.)can also be used in combination with the chromic change agent to give asparkle-like effect. More granular colorants can be used to give amatte-like finish to the coating.

Methods for Polymerization:

Polymerization can be accomplished either prior to processing with thefood or after the monomer has been processed with the food. Thephotochromic properties of the chromic material can be used to createpatterns and messages on the surface of solid foods. Increasing ordecreasing the level of polymerization of the chromic material is usedto increase or decrease, respectively, the temperature or other means ofinducing color changes in the polymer:food matrix or the like used totrigger a chromic change in the material. For example, different zonesof a food surface, which contains the chromic material, can bepolymerized to different levels. Each zone can, depending on the levelof polymerization exposure, change color sequentially as the temperaturerises. The chromic change zones can tell consumers that cooking is inprogress but not yet done. As cooking continues and as the last zonechanges color, the consumer can ascertain that cooking is complete.

Zones which change colors at increasing temperature can be used for foodsafety purposes indicating to preparers or consumers when the food iscooked to a temperature level and any contaminating bacteria have beenkilled (e.g., 160° F.). Zones would be calibrated to accommodate higherexternal temperatures during cooking.

Increasing or decreasing the localized concentration of chromic materialin combination with controlling the local level of polymerization can beused to create complex patterns on the surface of a food type.Increasing the local concentration in one area relative to another areawill create a higher relative triggering temperature in the highconcentration zone relative to the lower concentration zone. Thepatterns can be developed to create the visual appearance of a changinggraphic throughout the temperature triggering process.

In addition, standard food colors can be used in combination with thechromic material to create full color designs and patterns. The visualrepresentation of a graphic that changes color and apparent patternthroughout the heating process can have significant value in that it canbe used for commercial, promotional, merchandising and advertisementpurposes. In some cases, polymerization can be accomplished by theconsumer where, by opening a package and placing the foodstuff insunlight, a color begins to appear immediately prior to consumption. Forexample, drinks or cookies can be made to change color in the sun. Inother product formats, the photochromic food may be purchased along withan appliance or hand held ultraviolet lamp which can be use to exposethe photochromic material.

Thermal polymerization can be utilized in certain foods. Thermalpolymerization provides for photochromic color development of thechromic agent without the need for an external ultraviolet light source.Certain forms of diacetylenic compounds that are highly ordered, yetprovide flexibility for reorganization, can self-initiate polymerizationunder mild conditions. For example, the crystalline form of themethylester of 10,12-tricosadiynoic acid will polymerize in the dark andin absence of ultraviolet light. The thermal polymerization temperaturemay be substantially different from the thermal color change transitiontemperature. Polymerization may occur at a lower temperature, e.g.10-20° F., than the thermal transition temperature.

Patterns in the chromic agent can be generated by selectively placingthe agent in locations using methods such as ink jet, pad, extrusion oroffset printing followed by polymerization of the chromic agent.Alternatively, the patterns can be generated using a continuous evenlycoated area of the chromic agent followed by photo-masking techniques.Ultraviolet light-transmitting photomasks can be utilized. In eithercase, high-resolution graphics and line art can be generated directly onthe food surface.

Ingestible chromic change particles dispersed throughout ground meats asan intrinsic internal thermometer: The United States Department ofAgriculture now recommends not using the color of cooked ground meats todetermine doneness and whether or not that the meat has been cooked to asafe level (greater than 160° F.). The chromic change agent can find useas an element dispersed throughout ground meat that turns color onlywhen the center of the ground meat has reached an internal temperatureof 160° F. The chromic agent can be coated on any compatible food gradeadditive that can be admixed with the ground meat prior to cooking. Thechromic change agent/additive can be introduced into the ground meat atthe meat processor level or by the consumer immediately prior tocooking. Chromic change agent particles can be dispersed into groundmeats at a concentration that allows the particles to be visualized anytime the meat is exposed when cut open. The chromic change agentparticles can be dispersed at a concentration of one per centimetercubed to a concentration of 1000 per centimeter cubed. More often thechromic change agent particles can be dispersed at a concentration of 10per centimeter cubed to 500 per centimeter cubed. Usually, the chromicchange agent particles should be present from a concentration of 25 percentimeter cubed to a concentration of 100 per centimeter cubed. Chromicchange agent particles obviate the need for thermometers since the meatitself can posses the temperature sensing capability. The cook orconsumer need only cut into a piece of meat during cooking to determineaccurately the internal level of doneness of the meat being cooked.

Ingestible chromic change particles integrated into foods may find broaduse in cooking or warming other items as well. For example, they can beused for baked goods, in food service for monitoring holdingtemperatures, processed, precooked meats such as hot dogs, in foodprocessing, in microwaveable foods, and various other related productsor processing.

The chromic change agent can be conveniently coated onto a particle suchas a spice, sesame seed, oatmeal flake, protein particle, soy basedparticle, carbohydrate particle or any other food compatible matrixparticle that is of size which can be identified by eye. The chromicchange agent can be coated as a film on the surface of the particle togive the particle a characteristic color that is differentiated from theground meat with which it is admixed.

Chromic change agent particles can range in size and shape. Typicallythe chromic change agent can be a sphere, a disc, egg shaped, a flake, arandom globule, a ring, various geometric shapes, a rod or noodle shape,or the like. The chromic change agent particle can be as small as a 0.5millimeters along its longest axis so as to be visible by eye to as longas sever centimeters. More usually the chromic change agent will one to10 millimeters along its longest dimension and typically 2-5 millimetersin length.

Chromic transition conformational change as a depot release substance:The chromic transition may be used as a releasing mechanism fornutrients, vitamins, ingestibles, drugs or the like base on thestructural change that it can undergo when it is triggered from onecolor to another. For example, polydiacetylenic material is known toundergo a significant conformational change during its transition fromone color to another. The blue form of the polymer is well orderedsystem comprised of parallel strands of extended and conjugated doubleand triple bond units. Side chains and substituents are ordered alongwith the polymer backbone in a lattice structure. When the orderedmacromolecular structure is chromically triggered, it becomes disorderedand an open lattice. The chromic change mechanism can be used as a meansto release a substance embedded within the lattice matrix. Opening thematrix can be used to release the embedded constituents. The chromicprocess has a dual function: first, it can act as a releasing mechanismand second, it serves as a color change indicator as to when the releaseoccurs.

Wording or graphics printed on the side of over-the-counter orprescription drugs can be printed with a low temperature irreversiblethermochromic material, indicating to the consumer, pharmacist ormedical specialist that the drug has been stored at a safe temperatureor has been spoiled at a higher temperature.

A chromic change agent may be incorporated into throat lozenges to tellthe consumer that they have an elevated body temperature or fever.Alternatively, an aqueous form of the chromic material can be added to amouthwash, spray or gargle that changes color if the user has a fever.

Alternative Thermochromic Materials:

Alternative thermochromic materials that may have application asingestibles include leucodyes, transition melting waxes, pigments thatare released during hydration or shear, micro and nano-pigments,molybdenum, doped or undoped vanadium dioxide, mercuric iodide,indolinospirochromenes, spiropyrans, polythiophenes, polybi-thiophenes,di-b-napthospiropyrans or the like. Alternative chromic change agentscan be combined with food matrices using methods described earlier.Methods for the preparation of spiropyrans, including (Keum et al.(1995), Bull Korean Chem Soc 16: 1007), polythiophenes (Lévesque et al.(1996) Chem Materials 8: 2843) and various other chromic change agents(Brown et al., eds., (1972) Photochromism, in Techniques of Chemistry,Vol. 3; Durr et al., eds., (1990) Photochromism: Molecules and Systems(Studies in Organic Chemistry, 40)) have been described. All of theseabove references are incorporated herein by reference. Extensivemodification or encapsulation may be required with compounds such asthese to ensure safe ingestion and consumption without toxic sideeffects.

Compounds such as spiropyrans and the like are of interest where thethermochromic change agent exhibits a color at one temperature anddisappears when the temperature is altered. Spiropyrans,polydiacetylenes and other related materials that change color or becometransparent can be used to reveal messages or graphics when overcoatedon a permanent pigment. Making messages appear or disappear is ofinterest to the food and entertainment industries for promotional,marketing, and sales programs.

Combinations of Different Chromic Change Agents:

In some cases, multiple color changes may be desirable or required onsome products. Different chromic change agents or classes of agents thatchange color in response to different triggering mechanisms may be usedon a single product as distinct pH indicators, time temperatureindicators, dissolved gas color indicators, ionic strength indicators,moisture indicating materials, chemical color change indicators, variousphotochromic materials, various thermochromic materials, variousmechanochromic materials, or the like. Combinations of polydiacetylenes,indolinospirochromenes, spiropyrans, polybithiophenes, leucodyes,di-β-napthospiropyrans, and other intrinsic color change agents, can beused alone or in combination. Combinations of these chromic changeagents can be accomplished by either co-mixing different agentshomogeneously or selectively placing the different chromic agents inzones so that each agent can be triggered by its designated triggeringmethod.

A variety of optical effects and applications can be envisioned by usingmultiple chromic change agents either specifically patterned orcoprocessed. For example, a series of chromic change agents can bepatterned by a dot matrix or offset printing process such that the zonesor images of one type of chromic agent can be visualized at ambienttemperatures or conditions. When the ambient temperatures or conditionsare altered, such as processes including cooking, heating, foodpreparation, eating or digestion, the patterns change in response toparticular triggering mechanisms. The chromic change patterns can bespecified or preprogrammed to achieve particular memory effects that canbe entertaining and/or informative. Entertaining pattern changes finduse in promotional applications such as a color change process thatleads the consumer stepwise through food purchasing, preparation andconsumption. Multipart color images or patterns and/or conditions whichchange in a complex or intricate manner may necessitate the use ofmultiple chromic change agents. Patterns that appear on ingestibles dueto the response of chromic change agents include text, characters,images, symbols, branding identities, messages, icons, logos, artisticdesigns or decorative designs.

Complex color patterns comprising multiple chromic change agents may beused to communicate directions or recipes to a potential or actualconsumer. By way of example, a prepackaged food item may incorporate amessage on the item that suggests that the item be purchased. After thepackage is opened, exposure to air, light or room temperature may causethe disappearance of the first message and a second message such as “Nowadd substance A” to be displayed. Addition of substance A may induce achemical change that leads to a chromic agent-induced pattern change andthe next message, which may state, for example, “Now bake at 350° F.”,“Add substance B”, or the like. In addition to text-based messages, aningestible may be imprinted with a series of graphical or “universal”displays that direct the consumer to the next step. Examples ofingestibles that communicate directions may include food items,pharmaceuticals or pills, or disposable swabs or other devices thatrequire some degree of preparation by the preparer or consumer.

Complex information pattern changes also find use in diagnostics andsensing applications where the pattern change results when an ingestibleis consumed, digested and excreted, as described below.

Chromic Change Agents as Diagnostic Indicators:

Intrinsic color change agents that are irreversible in color change canbe used when it is important to preserve permanently or record aphysiological process. Intrinsic color change agents that are reversiblein color change can be used when it is important to record repeatedly aphysiological event and/or be able to trigger reversibly a chromicchange agent to confirm how it was originally recorded as a diagnosticmechanism.

The chromic change and substance release system can find use in variousingestibles where it is desirable to indicate to an individual or healthcare worker that a drug, nutrient, over-the-counter medicine or the likehas been appropriately released into the individual's digestive system.For example, a chewing gum or similar product that is retained in themouth rather than swallowed, and that contains a chromic change agentcombined with a drug for delivery by chewing, can change color due thesheering forces of chewing or from reaction with salivary chemicals orenzymes. The chromic transition and corresponding color change serves asan indicator to the individual that the substance has been fullyreleased from the gum and that further chewing is no longer necessary inorder to obtain the full effect of the substance.

A chromic change agent may be incorporated on an diagnostic ingestible,such as a throat lozenge, which indicates the presence of a pathogenicmicroorganism. Streptococcus pyogenes, the causative agent ofstreptococcal sore throat, is one such microorganism that may bedetected by this means. A chromic change agent may be associated withone of a binding pair such as an antibody, enzyme substrate, receptorligand, etc., that interacts directly or indirectly with themicroorganism or its products. For example, a chromic change agent maybe incorporated in the lozenge in a liposome or other lipid-basedcomposition that is modified by a lecithinase from the bacterium. Achromic change agent that interacts when it contacts salivary componentsor other bacterial metabolic processes or products could then changecolor upon release from the liposome. Alternatively, a chromic changeagent may be linked to one of a binding pair, and interaction with theother binding pair member causes a chemical change in the environment ofthe chromic change agent and a subsequent color change. An example wouldbe a chromic change agent bound to an enzyme substrate, wherein thesubstrate is specific for a particular microbial enzyme. The substratealters the pH or redox potential in the environment of the chromic agentwhen acted upon by the microbial enzyme, inducing a color change as aresult of a change in, for example, the ionization or redox potential ofthe chromic agent.

A diagnostic color change ingestible can be used by the medicalcommunity to evaluate a number of digestive tract disorders or bodilydysfunctions in vivo. Devices can be constructed with color changeagents in selective patterns alone or in combination where they areplaced on a carrier such as a pill-sized bead or the like, and thenconsumed. As the carrier is ingested and travels through the digestivetract, it encounters various points at which it can be triggered, andits color changes in a particular color-changing zone. As the digestiveprocess continues, the carrier can record the wellness or dysfunctionalstate of the digestive process. As the carrier is excreted during abowel movement it has a record of information of the digestive processand can be used to give the consumer or physician general or specificinformation about the digestive functionality in vivo. In order tofacilitate recovery and separation of the diagnostic color changeingestible from fecal matter, a separation means can be incorporatedinto the ingestible, such as, for example, a magnetic core.

Ingestibles incorporating chromic change agents may also find use as adetection method for bodily dysfunction such as ketosis or liverdysfunction resulting in the lack of ability to properly metabolizecertain food components. The resulting biochemical by-product in breathor saliva can act as a trigger for a color change in the chromic agent,the change indicating the presence of a bodily dysfunction. The chromicchange agent can be incorporated into a mouth wash, a gargle, a spray,or other convenient form that enables saliva or breath to come incontact with the chromic change agent and trigger a color change as anindication of a dysfunction.

EXAMPLES

Specific foods or other compositions that are taken orally that havebeen or can be used with the subject invention, as illustrative ofingestibles generally.

Kellogg's Pop-tarts Nabisco Cream of Wheat Marshmallows Kellogg's RiceCrispy Treats Easy Bake Oven Products Karo Syrup Kellogg's Fruit LoopsKraft Foods Jell-O Hormel Franks Bologna Pepperidge Farm Goldfish SoupCrackers Nabisco Newtons Flintstone Vitamins Turns Antacid CrestToothpaste Listerine Mouthwash

Throat lozengesFrench toast sticks Burger King Cinnamon Buns Pillsbury frostingCinnamon Minis—Special dip frosting—Burger King

Example 1 Synthesis of Chromic Agents Synthesis ofN-ethanol-hexadeca-5,7-diyneamide

1 molar equivalent 5,7-hexadecadiynoic acid (GFS Chemicals) wasdissolved in dichloromethane to a concentration of 100 mg/ml and stirredat room temperature. 1.05 equivalents of 1,1-dicyclohexyl carbodiimide(DCC) were added and the mixture stirred. An immediate white crystallineprecipitate formed indicating the presence of dicyclohexyl urea (DCU).The reaction mixture was stirred for 1 hour at room temperature.Ethanolamine (99.5% pure, Aldrich Chemicals) was added drop wise to theunfiltered stirring solution. The amide formation was checkedperiodically using TLC and spotting a filter paper then ultraviolet 254polymerization and testing reversible thermochromism (85° F. red/60° F.blue). The reaction was complete within 1 hour and left standing for atotal of 4 hours at room temperature. The DCU was filtered from thereaction mixture using gravity filtration (Whatman 541) and allowed tostand at 4° F. over night. Additional DCU crystals formed over night andwere filtered using gravity filtration (Whatman 541). The solvent andresidual ethanolamine was remove using a Rotovap. The reaction productwas resuspended in dichloromethane and refiltered using gravityfiltration (Whatman 541). The solvent was removed a second time using aRotovap. The reaction product was suspended in hexane/dichloromethanesolution (20/1 volume/volume). The suspension was warmed to near theboiling point of the solvent mixture to dissolve the product. Thereaction crystallization mixture was kept at room temperature for 6hours. The crystallized product was filtered using gravity filtration(Whatman 541), redissolved and recrystallized a second time.

N-ethanol-hexadeca-5,7-diyneamide can also be prepared by an alternatesynthetic route whereby the 5,7-Hexadecadlynoic acid can be converted toan acid chloride and added directly to a stirring solution containingethanolamine to yield the final amide product. This route has theadvantage of more direct purification since it eliminates the need toremove a coupling agent such as residual DCC or the DCU byproduct.

Synthesis of methyl 10,12-pentaeosadiynoate (MePDA)

10,12-pentacosadiynoic acid (10 gm., GFS Chemicals) was dissolved in asolution containing 10 ml methanol

(HPLC grade) and 10 ml chloroform (HPLC grade). The solution was stirredat room temperature and 10 drops of neat sulfuric acid was added dropwise. The solution was warmed to 100° F. for 2 hour. The reactionmixture was purified using column chromatography. The product (MePDA)was dried using a Rotovap and the material stored in a chloroformsolution. The solid form of MePDA was very unstable to polymerizationand therefore kept dissolved in organic solutions.

Synthesis of methyl 10,12-tricosadiynoate (MeTDA)

10,12-tricosadiynoic acid (10 gm., GFS Chemicals) was dissolved in asolution containing 10 ml methanol (HPLC grade) and 10 ml chloroform(HPLC grade). The solution was stirred at room temperature and 10 dropsof neat sulfuric acid was added drop wise. The solution was warmed to100° F. for 2 hour. The reaction mixture was purified using columnchromatography. The product (MeTDA) was dried using a Rotovap and thematerial stored in a chloroform solution. The solid form of MeTDA wasvery unstable to polymerization and therefore kept dissolved in organicsolutions. Alcoholic solutions of MePDA and MeTDA: Solids MePDA or MeTDAwere dissolved in reagent grade ethanol to a concentration of 150 mg/ml.A residual polymer was removed by filtration through Whatman No. 1filter paper. The solutions were held at room temperature or slightlyabove (70-75° F.) to avoid crystallization or precipitation.

Synthesis of dimethyl bis(10,12-pentacosadiynl oxyethyl) ammoniumchloride (BRONCO)

10,12-Pentacosadiynoic acid (5 gm. 13.4 mmol., GFS Chemicals) wasdissolved in 60 ml dichloromethane and filtered (Whatman No. 1)resulting in a colorless solution. 1,3-Dicyclohexylcarbodiimide (3.6 gm,17.5 mmol., Aldrich Chemical Corp.) and the base 4-dimethylaminopyridine(one equivalent, Aldrich Chemical Corp.) were added to the solution andstirred for 15-20 minutes during which time a white crystallineprecipitate, dicyclohexylurea, formed.Bis(2-hydroxyethyl)dimethylammonium chloride (1.14 gm., 6.68 mmol.,Acros Organics-Fisher Scientific) was added to the reaction mixture andstirred over night in a dry inert atmosphere (nitrogen). The ureaprecipitate was filtered out using (Whatman No. 1) and the reactionmixture was purified using column chromatography. Dimethylbis(10,12-pentacosadiynl oxyethyl)ammonium chloride, Bronco, was driedusing Rotovap and stored in a powder form.

Alcoholic Monomer Solution of TDA/PDA:

10,12-Tricosadiynoic acid (TDA, 6 gm GFS Chemicals) and10,12-pentacosadiynoic acid (PDA, 0.9 gm GFS Chemicals) were dissolvedin 60 ml ethanol (Fisher). The solution was slightly warmed and stirred.The solution (TDA/PDA) was filtered (Whatman No. 1) to remove residualpolymer. Dye colorant could be added to the alcoholic monomer solutionas an indicator. Standard organic solvent based dyes were added at 2drops per ml.

Example 2 Preparation of Edible Printed Laminates

Ink Jet Printing

Black ink jet cartridges (Hewlett Packard 680C compatible or CannonBJC2000) were modified to contain either the TDAIPDA or MePDA alcoholicmonomer solutions. The cartridges were opened and the water based inkremoved. The cartridges were flushed with ethanol and the alcoholicmonomer solutions added separately to each cartridge. The cartridgeswere sealed, purged, and inserted into an ink jet printer (HewlettPackard 680C or Canon BJC2000). Standard word processing and graphicsprograms were utilized for printing. The ink jet cartridges were cleanedperiodically to remove residual build up of monomer caused by drying.

Ink Jet Printed Thermochromic Sugar Laminates:

Edible laminates for ink jet printing (Kopykake, Torrance, Calif.) wereprinted using the TDA/PDA or MePDA monomer solutions, food grade ink jetdyes, and the ink jet printing systems described above.

Air Brush Coating Surfaces: Alcoholic solutions contain TDA, PDA,TDA/PDA mixtures, or MePDA or an aqueous solution containing BRONCO wereprepared according to the methods described above and sprayed onto foodsurface using a standard hand held air brush Badger model 200, USA).Solutions were thinned or concentrated with their corresponding solventto achieve desired coating. Coating was accomplished by applying asteady stream of vaporized material to the surface at a distance of 1-6inches. Patterns were formed using paper stencils or by careful handmovement. After coatings were applied and allowed to dry, the surfaceswere polymerized using a hand held ultraviolet lamp (254 nm).

Example 3 Temperature Triggered Chromic Change Agents 1. TemperatureIndicating Ingestibles

130-150° F. Thermochromic Corn Syrup:

Temperature indicating syrup for hot pancakes, waffles, or the like weremade using a microcrystalline suspension of a polymeric polydiacetylene.2 gm 10,12-tricosadiynoic acid was mixed with 45 ml corn syrup (Karobrand Best Foods, Englewood Cliffs, N.J.) and then probe sonicated at40% power using a 400 watt sonicator (Cole Parmer Instruments, VernonHills, Ill.) for 5 minutes. The sample heated to about 140° F. duringsonication. After uniform mixing, the sample was allowed to cool to roomtemperature (3 hours). A white cloudy suspension appeared within 1 hour.The sample was mixed using a stir rod until a creamy consistencyresulted. The sample was polymerized to a deep dark blue color in ashallow plastic container using a hand held ultraviolet lamp (254 nm,Cole Parmer Instruments, Vernon Hills, Ill.). The sample was irradiatedfor 4 minutes and mixed using a stir rod.

The dark blue syrup was immediately available for use with hot foods.The syrup could easily be spread on hot toast or waffles. Uponapplication to the food, the dark blue syrup turned bright red in colorindicating the surface temperature of the hot food it was applied to.The thermochromic transition temperature occurred at between 130° F. to150° F.

110-130° F. Thermochromic Corn Syrup:

Moderate temperature triggering corn syrup was made using theformulation described above and by adding absolute ethanol at 5% byvolume. The ethanol was added to a premixed unpolymerized suspension.The suspension and ethanol were mixed to uniformity for 5 minutes atroom temperature and polymerized using the identical conditionsdescribed above. The thermochromic transition temperature of thepolymerized mixture occurred at between 110° F. to 130° F.

Temperature Indicating Thermochromic Icing/Syrup:

5 ml of the MePDA alcohol solution (above) and 10 gm cake icing(Signature Brands, LLC, Ocala, Fla.) were uniformly mixed at roomtemperature for 10 minutes. Most of the ethanol from the solutionevaporated. The resulting creamy paste was chilled to below freezing(−10° F.) and then exposed to an ultraviolet lamp (hand held, 254 nm)for 5-10 minutes while remaining chilled. The mixture was churned duringexposure to give a uniform blue appearance. The thermochromic icing wastemperature triggered by simply raising it above freezing (greater than50° F.). The icing immediately turned bright red when applied tosurfaces exposed to room temperature, directly exposed to roomtemperature, or touched by directly by hand. Oils contained within theicing helped to facilitate the temperature triggering of thethermochromic agent in the icing. Partially hydrogenated vegetable oils(soybean and cottonseed) are solid in nature at freezing temperatures,keeping the blue polymeric MePDA stable. As the oils melt at above roomtemperature, the polymeric MePDA is subsequently influenced totransition from a dark blue color to a bright red. The icing was furtherpackaged in air sealed plastic pouches (4 mil, polyethylene) andheat-sealed using a conventional heat sealer. Care was taken not toexpose or contact the dark blue frosting to temperatures above freezing.The frosting/syrup could conveniently be extruded onto a pastry surface.During the application, the dark blue color turned immediately brightred due to finger contact with the pouch and exposure to a roomtemperature surface.

Low Temperature Indicating Marshmallows:

Marshmallows were quickly dip coated into the MePDA alcohol solution andallowed to dry at room temperature or below. The monomer dip coatedmarshmallows were exposed to ultraviolet light (hand held lamp, 254 nm)and rotated for uniform polymerization (approximately 2 minutes) untilthey became dark blue. The marshmallows were stable at room temperatureor below (68° F.). They immediately changed to a bright red/orange colorupon direct touching, contact with warm fluids, or placing in thepresence of an open flame (95° F. or above).

High Temperature-indicating Hot Chocolate:

Yellow dye number 6, red dye number 40, and a medium bluepolydiacetylenic thermochromic agent that turns orange when triggered byheating were added to a hot chocolate mix prepared at room temperature.The resulting combination of hot chocolate, dyes and thermochromic agentwas brown in color. When hot water was added to the solution, the browncolor changed to a combination of yellow and red, bringing the brown mixto a bright orange color.

2. Cooking State-Indicating Ingestibles

Temperature Indicating Frozen Waffles:

Frozen waffles (Eggo brand, Kellogg Company) were removed from theirpackage and immediately sprayed with an alcohol based monomer solution(above). Waffles were coated at 68° F. using a standard airbrush.Patterns were created using the square cells on each waffle. The monomersolution dried immediately on the waffle surface. The monomer-coatedwaffles were polymerized using a hand held ultraviolet lamp (254 nm, 6inches for 10 to 60 seconds). Radial polymerization gradients were usedto increase the level of polymerization from the outer region of thewaffle to the center. Increasing the level of polymerization causes acorresponding increase in the final colorimetric temperature transitionof the thermochromic agent. The resulting waffles had a dark blueappearance upon polymerization. The patterned thermochromic indicatingwaffles were conveniently re-stored in the freezer prior to use. Thetemperature indicating waffles were toasted using normal instructions onthe package. As the waffles were heated, the dark blue color changed toa bright red/orange. The outer portions of dark blue changed colorfirst. As heating continued, the inner portions of blue at the center ofthe waffles turned color to red/orange last. The color transition wascomplete when the waffles were fully heated indicating that toasting wascomplete and the waffles ready to serve.

Ground Meat Patty Possessing a Chromic Change Agent Particle forIndicating Internal Safe Cooking Temperatures:

Chromic change particles were prepared by coating sesame seeds with athin layer of a chromic change agent. An ethanol solution was preparedwith ethanol (Spectrum Chemicals, Inc.) containing 150 mg/ml10,12-tricosadiynoic acid and 15 mg/ml 10,12 pentacosadiynoic acid. Thesolution was warmed to 100° F. to dissolve all of the diacetylenic acid.10 gm sesame seeds were placed in a screw cap vial and saturated with 2ml of ethanolic solution. The seeds and solution were shaken and tumbledfor 3 minutes to ensure complete coverage of each seed. The seeds werepoured into a Teflon coated dish and tumbled for 10 minutes with agentle air stream to ensure that all of the ethanol solution wasremoved. The coated particles were vigorously shaken and exposed toultraviolet light (hand held lamp, Cole Parmer, Inc. 254 nm) for 5minutes resulting in the deep blue appearance of the polydiacetylenicpolymer. The coated particles were stored overnight at room temperature.

The blue polymer coated particles were admixed with ground hamburgermeat to a concentration where multiple particles were present in thecentral region of a patty each time a patty was sliced through Pattieswas grilled on a gas grill and flipped over during cooking. The centerof patties were systematically tested during grilling to determine theextent of color change during cooking. Color change particles toward theouter segments of a patty turned color to a bright red/orange earliestduring cooking. Color change particles in the center of a burger turnedcolor to a bright red/orange once the burger's internal temperatureachieved 160° F. indicating that the burger was cooked thoroughly.

Baby Food:

The likelihood that a child will be burned by ingesting overly-heatedbaby food solids and liquids may be significantly reduced by using acolor reversible thermochromic agent combined with a food or formula.Solid foods or formulae may be prepared with a blue thermochromic agent.Upon heating the food or formula the thermochromic agent changes colorto orange, indicating a high temperature, which then reverts to the bluecolor when the temperature of the food or formula is safe to ingest. Thethermochromic agent can also be used to indicate uneven temperaturedistribution in various regions of the food or formula, and that thefood should be mixed to achieve a more uniform, safe temperature.

Thermochromic Graphically Patterned PopTarts:

PopTarts (Kellogg Company) were coated with a commercially availablesugar glaze and allowed to dry for several hours at room temperature.Edible laminates jet printed (Kopykake, Torrance, Calif.) with eitherTDAIPDA or MePDA monomer solutions and the Kopyjet ink jet printingsystem as described above were applied to the glazed PopTart surface.Initially the glaze surfaces were slightly wetted to facilitate theadherence of the edible laminate. Various entertaining patterns weregraphically rendered for application on the PopTarts. The monomerprinted surfaces were polymerized using a hand held ultraviolet lamp(254 nm) at a distance of 3 inches for 5 to 10 seconds depending on thedesired level of blue color. TDA/PDA printed/polymerized PopTartschanged color from a dark blue to a bright red/orange when exposed totoaster or microwave temperatures. MePDA printed/polymerized PopTartschanged color from a dark blue to a bright red/orange when exposed tofinger touch or above 90° F.

Franks and Hot Dogs:

Processed hot dogs can be impregnated with a thermochromic materialwhich turns color when a specific heat is achieved. The material can bepatterned such that lettering may indicate the words “HOT DOG” forpromotional and advertisement value. Conveniently, an aqueous form ofthe thermochromic agent is ink jet printed into a pattern representingwords of interest. The polymerizable dual chain lipid BRONCO wassuspended in water and pre-polymerize with ultraviolet light (254 nm) atroom temperature to a dark blue ink color. The polymer solution wasprinted on the side of a retail available hot dog (Hormel or Kraft). Thechromic agent can also be printed on the meat product cellulosic casingprior to filling the casing with processed meats and fillers. Casingsare typically extruded, processed, and dried prior to filling. Printingon the unfilled casing provides the advantage of printing on a dry solidsurface using high speed printing and drying methods with out effectingthe foodstuff. Printing on the casing can involve ink jet printing, padprinting, masking, spraying, silk screening, extrusion or the like.

Brownie Mix:

Brownie mixes were prepared by incorporating a blue thermochromic agentthat changes to bright orange upon heating. Upon preparation of thebrownie mix according to the manufacturer's directions and baking, thedark brown mix became bright orange. The thermochromic agent thus servedas both an entertaining color change component of the mix, and as anindicator that the brownies were done and ready to be removed from theoven.

Embedded Food Bar Codes:

Embedded thermochromic bar codes produced directly on the side of apre-baked ham cut. A thermochromic bar code allows a standard bar codeand bare code reader to be used as a thermometer device. An alcoholicsolution containing TDAIPDA (described above) was sprayed locally on theside of a 1 pound piece of pre-cooked ham (Hormel Company). The hamsurface was prepared by damp drying a 1×2 inch region. The region wassprayed at a distance of 3 inches using an airbrush as described above.An ultraviolet transmissive photomask with a negative bar code patternwas prepared using a black film thermal transfer printer (Brother) and8.5×11 inch sheet of 4 mil thick clear polyethylene sheet. The bar codephotomask, sized to 0.75 by 1.5 inch, was placed directly over thesprayed region of TDA/PDA. The bars in the code were transmissive toultraviolet light (254 nm). The bars were selectively exposed using alight shield over certain bars while others were exposed. This methodallowed some bars to be polymerized for 100% more time than others didso that the lesser exposed bars would change color at lower temperatures(125° F.) and the more highly exposed bars would change color at highertemperatures (170° F.). The differential temperatures were set so that abar code reader could read while ham was hot so that the bar codescanner could interpret the disappearance of certain bars (due to thedark blue to red color transition during heating) as being a differentcode than when it started. The scanner information was converteddigitally using a standard computer so that the corresponding computeroutput could indicate the actual temperature.

3. Decoration of Ingestibles

Thermochromic Cereals:

A low temperature reversible thermochrome can be prepared in a versatilepolyethylene glycol coating. A coating solution containing thepolymerizable monomer N-ethanol-hexadeca-5,7-diyneamide (100 mg/ml)3,350 molecular weight polyethylene glycol (750 mg/ml) was made in anethanol (absolute) by warming to 120° F. and mixing. The viscoussolution remained clear above 100° F. The coating solution is slightlyviscous and easily applied to a food surface by blotting, painting, orspraying. Both the N-ethanol-hexadeca-5,7-diyneamide and polyethyleneglycol crystallize from solution upon cooling to room temperature andsolvent evaporation. Foods cereals such as Kellogg's Frosted Miniwheatswere coated by painting with a thin coat and allowed to dry at roomtemperature for 2 hours. The resulting coat dried to a hard wax-likeappearance. The N-ethanolhexadeca-5,7-diyneamide was polymerized using ahand-held ultraviolet lamp (254 rim, 6 inch distance) for a totalexposure time of 1 minute. The resulting layer became strongly magentaat room temperature 68 72° F.), bright red/orange at increasingtemperature (85-95° F.), and dark blue/purple when chilled (35-55° F.).The color change is completely reversible as long as the uppertemperature level is maintained below 130° F. The coated cereal piecesturn from a bright magenta/red to dark purple/blue when cold milk ispoured over their surface (42° F.). The dark purple/blue color remainsas long as the milk remains cold. The color is thermochromicallyreversible through hot and cold cycles.

Processed Thin Sliced Cheese:

Pre-packaged thin sliced cheese can be printed with the aqueous solutionof the thermochromic agent. The solution can be pre-polymerized or in amonomeric form which can be polymerized after printing. Thethermochromic agent is absorbed to the cheese surface upon brief dryingcausing a strong bonding to occur between the thermochromic agent andthe surface of the cheese.

A pattern of the American flag was produced on the surface of a thinslice of American cheese (Kraft 2% Milk Reduced Fat Milk Singles). Thepattern was painted using a thin brush and a dark blue solution ofpre-polymerized BRONCO. The pattern was allowed to dry at roomtemperature for 5 minutes and the cheese repackaged for storage.

The flag-painted slice of cheese was placed on a hamburger while theburger was cooking on a grill. Within 2-3 minutes, the cheese began tomelt. During heating and melting, the dark blue flag pattern becamebright red. The flag pattern also started to flow and contort as thecheese melted and flowed. The flow process gave rise to an interestingeffect, simulating a waving and moving flag.

Thermochromic Sugars, Salts, Spices, Cheese Powders, Grated Cheese, andShredded Cheese:

An ethanol coating solution was prepared with ethanol (SpectrumChemicals Inc.) containing 150 mg/ml 10,12-tricosadiynoic acid (GFSChemicals, Inc.). The solution was warmed to 100° F. to dissolve all ofthe diacetylenic acid. Twenty grams of sugar, salt, spice (e.g. paprikaor mustard seeds), or cheese powder (e.g. Parmesan cheese or powderedcheese from Kraft Macaroni and Cheese mix) were added to a screw capbottle and saturated with up to 2.5 ml of the ethanolic solution. Apowder and solution were shaken and tumbled for 3 minutes to ensurecomplete coverage of the particles. The solution wetted powders werepoured into a Teflon coated dish and tumbled for 10 minutes with agentle air stream to ensure that all of the ethanol solution wasremoved. The coated powders were vigorously shaken and exposed toultraviolet light (hand held lamp, Cole Parmer, Inc. 254 nm) for 5minutes resulting in the deep blue appearance of the polydiacetylenicpolymer. Once dry, the coated powders could be used immediately.

Thermochromic triggering was accomplished by applying a powder typedirectly to a heated food type. For example, the chromic agent coatedpowder cheese was added to a pre-heated/cooked bowl of macaroni. Oncontact, the dark blue cheese powder turns to a vivid red orange color.Visual effects can be created by first adding a small pile of thetreated pile to a hot food. At first the shallow edges turn orange andthen the blue pile gradually turns orange with the orange colorradiating inward until finally the peak is triggered orange.Alternatively, the coated powder can be sparsely sprinkled on the foodsuch that each grain turns color instantly.

Thermochromic Soup Crackers:

Soup crackers (e.g., Pepperidge Farms Fish Cracker brand or standardsoup crackers) were lightly sprayed and wetted with an adhesive foodglaze (150 mg/ml water soluble starch dissolved in purified watersprayed with a nebulizer). The lightly wetted surface was tacky to thetouch for several minutes prior to drying. While the surface was tacky,the crackers were coated with a thermochromic salt powder as prepareabove. The coated salt particles adhered to the cracker surface once theadhesive food glaze dried. The final crackers revealed a blue tint, ontheir surface. The optical density of blue color was regulated by theamount of coated salt applied.

Thermochromic triggering was accomplished by dipping a cracker into ahot bowl of soup. The dark blue tint on the cracker surface turnedimmediately to a bright orange on contact with the hot liquid. Visualeffects were created by dipping the crackers at various depths andangles into the soup.

4. Storage Temperature Condition Indicators

Raw Egg Holding Temperature Indicator:

Eggs were printed with the alcoholic solution containing MeTDA describedabove. The monomer solution was spot printed using a porous felt padsaturated with the monomer solution. Printing was conducted while theeggs were held at 40° F. The monomer was allowed to dry for 2 minutesand polymerized at using a hand held ultraviolet lamp (254 nm) at 40° F.The dark blue printed spot held its color on an egg until the egg wasraised to between 55 to 65° F. were the dark blue spot became brightred/orange indicate that the egg was exposed to an excessive holdingtemperature range. Eggs should be kept at refrigerator temperatureduring storage due to the potential contamination of Salmonella and thepossibility of cell replication at above refrigerator temperatures.

Example 4 Mechanical Stress-Triggered Chromic Change Agents

Candies and Cookies Possessing Mechanically Induced Color Changes:

Hard candies such as jaw breakers, M & M's, hard coated gum pieces, hardicing coated cookies, or the like were coated with a color change agentthat changes color due to mechanical and/or frictional forces applied tothe surface with the mechanochromic agent. An ethanol coating solutionwas prepared with ethanol (Spectrum Chemicals, Inc.) containing 200mg/ml 10,12-octadecadlynoic acid (GFS Chemicals, Inc.). The solution wasspray coated onto candy or cookie surfaces using a conventional airbrush system. The coating can be applied either while the candy orcookie surface is stationary or tumbling. Once an even coat has beenapplied, the surfaces are allowed to dry at room temperature of 30minutes. The coated surfaces are polymerized using an ultraviolet light(hand held lamp, Cole Parmer Inc. 254 nm) for 5 minutes resulting in theblue appearance of the polydiacetylenic polymer.

Candy and cookie surfaces coated with the blue polydiacetylene layer arechanged to a red/orange color by rubbing surfaces together, rubbing witha finger or finger nail, or rubbing with a compatible hard surface.Surfaces with temperature insulative properties such as finger nails,napkins, wood sticks, paper dowels, plastic sticks or the like aresuperior for inducing the color change compared with metal or glasssurfaces which have heat conductive surfaces. Patterns, messages, andgraphical images can be created on the mechanochromic surface bylocalized rubbing without changing the color of an adjacent region ofthe blue mechanochromic agent.

Mechanochromic Tooth Paste:

A ratio of 10 g Crest Tooth Paste with 1 gram pre-polymerize flakes of5,7-hexadecadiynoic was mixed at room temperature to become a blue pastecontaining small blue particles of the diacetylenic polymer.5,7-hexadecadiynoic acid (GFS Chemicals, Inc.) flake-like crystals werepolymerized to a dark blue tint using a hand-held ultraviolet lamp (ColeParmer inc.) for 3 minutes. The flakes were agitated during the processto ensure complete polymerization. The dark blue flakes were added totooth paste at room temperature and mixed thoroughly. The finalformulation was stable at room temperature. The mechanochromic toothpaste turned form a dark blue paste to a pink/purple color when thetooth paste was abraded back and forth with a standard tooth brush(medium bristles) for 2-3 minutes.

Touch Sensitive Rice Krispie® Treats:

Retail Rice Krispie Treats (Kellogg Company) were air brush spray coatedusing the method described above and an alcoholic solution of MePDAprepared as described above. The Rice Krispie Treats surfaces wereinclined at 30 degrees on an open tray and sprayed at a distance of 4inches using a moderate stream flow from the airbrush. The coatings wereallowed to dry for 5 minutes at 65 g. Pattern coating was accomplishedusing an open letter stencil and spraying just beyond the outline of thestencil. Polymerization was accomplished using a hand held ultravioletlamp (254 nm) moved back and forth over the surface for 5 seconds at adistance of 3 inches. The surface immediately became dark blue and couldbe made to change color to a bright red/orange by finger touch,breathing on the surface, or biting into the surface.

Example 5 Combined Temperature-Mechanical Stress-Triggered ChromicChange Agents

Combined Photochromic Thermochromic-Mechanochromic Cookies:

An ethanol solution was prepared with ethanol (Spectrum Chemicals, Inc.)containing 150 mg/ml 10,12-tricosadiynoic acid and 15 mg/ml10,12-pentacosadiynoic acid. The solution was warmed to 100° F. todissolve all of the diacetylenic acid. The solution was loaded into anemptied, cleaned, and dried ink jet cartridge (Hewlett Packard HP51629A). The cartridge was placed in an ink jet printer (HewlettPackard, Deskwriter 680C). The printing room and printing componentswere maintained at a temperature of 95° F. to ensure that the ethanolprinting solution remained soluble. Edible laminates (Kopykake Inc.,Torrance, Calif.) were printed using standard graphics programs andinterfaces.

Graphical images were printed on the laminate and then adhered to thesurface of cookies. The cookies were place in the sun or exposed to ahand held ultraviolet light source (Cole Parmer, Inc.). The graphicalimages appeared exactly as they were printed upon exposure. Thegraphical images became visible within minutes in sun light (peakintensity at 12:00 noon during the spring time in California). The colorbecame progressively darker with continued exposure up to hours.

The dark blue images printed on the cookies could be subsequentlytriggered to a bright red upon heating the cookie or dipping it in hotliquid (milk heated to 130° F.). Variations ultraviolet activated colordevelopment times and thermochromic temperature transitions can beachieved by modifying the polydiacetylene structure utilized.

The blue polydiacetylenic images on the cookie surface can also undergoa mechanochromic transition to a red/orange color by mildly rubbing theimage/cookie surface. The mechanochromic effect is highly localized tothe specific are being contacted. The image can be graphically alteredby localized rubbing to achieve different graphical effects based onmultiple colors (e.g. the background cookie color, the blue form of thepolymer, and the red/orange form of the polymer).

Example 6 Combined Temperature-Chemical Triggered Chromic Change Agents

Chromic Change Liquid Beverage with Dual Function:

An aqueous suspension 100 mg/ml of N-ethanol-hexadeca-5,7-diyneamide wasprepared using ultrasonication and lecithin as an emulsifier. One gramN-ethanol-hexadeca-5,7-diyneamide (prepared as described in this patent)and 1 gram egg lecithin (Sigma Chemicals, Inc.) were added to a glassbeaker along with 30 ml filtered water and sonicated with a high powerprobe sonicator (Cole Parmer, Inc.) for 10 minutes at 130° F.Homogeneous suspension formation required agitation and mixing. Thefinal suspension was milky white. The suspension was allowed to cool toroom temperature and left to stand 24 hours. The suspension wasdispersed by mixing or agitation. Five ml of the solution was added to ashallow dish and exposed to ultraviolet light (hand held lamp, ColeParmer, Inc. 254 nm) for 5 minutes (with continual mixing and agitation)resulting in the deep magenta appearance of the polydiacetylenic polymer(room temperature). The magenta color chromic solution could be dilutedwith water or kept concentrated.

For thermochromic conversion, a 5 fold diluted solution of the chromicsolution (purified water) was poured over crushed ice in a clear glass.The color immediately changed to a dark purple/blue color upon chilling.The solution color was thermochromically reversible when rewarmed toroom temperature and subsequently chilled back to near freezingtemperatures. Temperature cycling could be repeated numerous times.

For chemochromic conversion the chilled purple/blue chromic solution canbe further changed to a bright pink/orange color by the addition ofalcohol (chilled or ambient in temperature). Addition of an increasingconcentration of alcohol caused the purple/blue color to progressivelyturn irreversibly to a pink/orange color. When greater than 50% alcohol(volume/volume water/alcohol) is added the solution becomes completelypink/orange. The system serves as a means to detect the presence ofpolar solvents such as alcohol or acetone.

Example 7 Moisture Triggered Chromic Change Agents

Hydrochromic Ingestible Sugar, Sprinkles, Nonpareil and Salt Powders:

An ethanol coating solution was prepared with ethanol (SpectrumChemicals, Inc.) containing 130 mg/ml 4,6-decadiyne-1,10-diol (GFSChemicals, inc.). 20 grams sugar or salt powder were added to a screwcap bottle and saturated with up to 2.5 ml of the ethanolic solution. Apowder and solution were shaken and tumbled for 5 minutes to ensurecomplete coverage of the particles. The solution wetted powders werepoured into a Teflon coated dish and tumbled for 10 minutes with agentle air stream to ensure that all of the ethanol solution was removedand the coated powder consisted of a in a fine grain mesh with outclumps. The coated powders were vigorously shaken and exposed toultraviolet light (hand held lamp, Cole. Parmer, inc. 254 nm) for 5minutes resulting in the deep blue/purple appearance of thepolydiacetylenic polymer. Once polymerized the coated powders could beused immediately. Hydrochromic powders were stored at room temperatureof below in sealed jars and desiccants.

Hydrochromic powders were adhered to food surfaces such as cereals,cookies, crackers or any other food type intended to come in contactwith an aqueous medium. For example, a hydrochromic sugar can be coatedon the surface of a cookie intended of dipping in milk. The visualappearance of the blue/purple sugar powder can be enhanced bypre-coating the cookie with a bright white royal hard sugar icing.Immediately prior to the final drying stage of icing, a hydrochromicsugar powder can be layered on to the icing surface. Residual water inthe cookie icing will not change the outward surface color of thehydrochromic sugar powder as long as the water content in the icing isminimized and the grains do not wet. A gentle air stream over thecoating facilitates drying. Alternatively a tacky adhering glaze can beused for coating the food surface with the powder. The blue/purplepowder can be coated at a density practical for viewing.

Hydrochromic triggering is accomplished by dipping a coated cookie intochilled milk (liquid at room temperature or as low as 45° F.). Theblue/purple color changes to a bright orange on wetting. The colorchange within seconds using liquids at near room temperature and has adelayed effect over 30 to 90 seconds using liquids well below roomtemperature (45° F. to 55° F.).

Powders with very thin coats of the hydrochromic agent change color morerapidly than coatings that are thick since thicker coatings arerestrictive in letting water rapidly intercalate into the chromicagent's interstitial layer. The visual effect of hydrochromic colorchange can be regulated depending on the food type of interest.Hydrochromic coatings can also find use as integrated indicators thatfoods have been properly sealed form moisture there by ensuringfreshness and dryness during storage.

It is evident from the above description and results that by using athermochromic agent that undergoes a color change, many applicationsaccrue. The thermochromic agent may be applied to a wide variety ofingestibles in a wide variety of manners, incorporated into theingestible, particularly liquids, or associated with the ingestible,such as on packaging materials. The thermochromic composition can beused to ensure that an ingestible has been stored safely, that it hasbeen cooked to a desirable temperature, that it has cooled to a desiredtemperature, or solely for marketing or entertainment purposes. Exposureof ingestibles comprising moisture-sensitive chromic change agents tosolutions or moist atmospheres can provide entertaining color changes orreveal text or imaged based messages. Mechanical stress-triggeredchromic change agents that change color due to mechanical and/orfrictional force may be incorporated into a variety of ingestibles thatare rubbed, scratched, chewed, compressed, or the like, and findparticular use in toothpastes and touch-sensitive ingestibles.Ingestibles incorporating a number of different chromic change agentcombinations are provided that can reveal different text messages orimages and sequentially-displayed text or images based on the types oftreatments to which the ingestible is exposed. These messages may serveto direct the user to the next step in a preparation process, revealhidden messages, and serve as diagnostic indicators. The compositionsare physiologically safe and may be modified to be appropriate as to aparticular temperature transition and compatible with the ingestible.

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

The invention now being fully described, it will be apparent to one ofordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit or scope of the appendedclaims.

1-7. (canceled)
 8. A method for detecting whether an ingestible has beenexposed to an absolute temperature level, said method comprising:associating with said ingestible a diacetylenic compound that undergoesan irreversible color change when subjected to a change in temperature,wherein a color change associated with said ingestible is indicativethat said ingestible has been exposed to said absolute temperaturelevel.
 9. The method according to claim 8, wherein said diacetyleniccompound is attached to a container or packaging material foringestibles.
 10. The method according to claim 8, wherein said colorchange indicates said ingestible has been spoiled.
 11. The methodaccording to claim 8, wherein said color change indicates saidingestible is cooked. 12-20. (canceled)
 21. A method for manufacturingan ingestible comprising a diacetylenic compound, said method comprisingapplying said diacetylenic compound in a composition of up to 75% weight% of a diacetylenic compound.
 22. The method according to claim 21,whereby said composition is up to about 60% weight % of a diacetyleniccompound.
 23. The method according to claim 21, whereby said compositionof up to about 20% weight % of a diacetylenic compound.
 24. The methodaccording to claim 21, wherein said diacetylenic compound is a lipidmono- or dicarboxylic non-oxo carbonyl monomer, or derivative thereof.25-28. (canceled)
 29. An ingestible comprising a chromic change agentthat undergoes a color change one or more times in response to at leastone physical or chemical triggering mechanism.